Sonic the Hedgehog (2006)

Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ) is a platform video game that was made to celebrate the 15th anniversary of the Sonic the Hedgehog franchise. It was developed by Sonic Team and published by Sega for the Xbox 360 and PlayStation 3. It introduced the recurring character Silver the Hedgehog. It is the first ever Sonic game to support high definition graphics.

The game has been referred to by a number of different aliases, Its most popular alias is Sonic '06, other aliases are Sonic 2006, Sonic: 15th Anniversary, Sonic 360 and Sonic Next-Gen. Most of these nicknames were coined by the Sonic fandom.

The game faced development issues which resulted the product being rushed and ultimately a poor product being delivered. Upon release, it was widely criticized for its numerous gameplay glitches, long loading times and complicated plot.

Development
Beginning development after Shadow the Hedgehog, Sonic the Hedgehog was meant to be a rebirth of the series, the idea emerging from the question "What if Sonic the Hedgehog existed in the real world?", and was intended to take elements that people had praised in the preceding Adventure titles and bring Sonic "back to his roots." Nothing pointed more to the idea of using this game to celebrate what made Sonic the Hedgehog the "Most Famous Hedgehog In The World" than naming the game after the first in the series. However, instead of keeping things simple, Sonic Team came up with numerous ideas they wanted to include, to make the game the ultimate Sonic experience.

The advertising of Sonic the Hedgehog was first announced at the E3 convention in May 2005. At the 2005 Tokyo Game Show convention, Yuji Naka revealed the game's official title, Sonic the Hedgehog, and announced that it would celebrate the 15th anniversary of the Sonic the Hedgehog series. Game director Shun Nakamura demonstrated the game's use of the Havok engine during Sega's stage shows. In addition to consoles, the game was also to be available on the PC.

After its debut, the game's development team faced serious problems, starting with the resignation of Yuji Naka as the head of Sonic Team and the Executive Producer of the game. When presented with development kits for the Nintendo Wii, it was decided that Sonic the Hedgehog ' s staff would be split in two, with director Shun Nakamura finishing the creation of Sonic the Hedgehog for the Xbox 360 and PlayStation 3 consoles, while Yojiro Ogawa would use the other half of Sonic Team to begin work on Sonic and the Secret Rings for the Wii rather than port the "next-generation" game to the Wii's weaker hardware. What was originally an ambitious undertaking now became a race against time to meet the game's deadline with only half of a development team. In this time, Sonic Team reportedly ignored Quality Assurance Tester bug reports in their rush to have the game ready for Christmas of 2006 regardless of the consequences. As a result, the game was released with a lot of problems, which resulted in the game being heavily critically panned.

In February 2007, an interview with Sonic Team's producer Yojiro Ogawa was made to comment on what made the game looks like it is now, in which he replied: "The reason why we probably ended up with what we see today, involves a lot of reasons. One is that we did want to launch the title around Christmas, and we had the PS3 launch coming up, but we had to develop for Microsoft's 360 at the same time and the team had an awful lot of pressure on them. It was very hard for the team to try and see how we were going to come out with both versions together with just the one team. It was a big challenge."

Interestingly, insight into the development of the game's story, as well as selected concept art, was leaked to the Internet before the game was released in the form of a file called "SONICNEXT_allscript", which had all the storyline ported in XML format and was given to a fan site.

On June 23, 2018 Shiro Maekawa answered several questions about the game. He said that Sonic Adventure 2 and Sonic the Hedgehog (2006) were the hardest to write. The story of Sonic the Hedgehog was so complex that after it was completed, it felt like they had solved a puzzle. During the production of Sonic 06, he was told by Shun Nakamura that he wanted a story that was similar to Sonic Adventure 2. The requirements were that Silver has to come from the future and that he has psychokinetic powers, and that there have to be Sonic, Silver and Shadow stories. Maekawa was in charge of scene composition and writing key dialogue. Certain small parts were written by Kiyoko Yoshimura.

Sonic Episode

 * For the script of this storyline, see Sonic the Hedgehog (2006)/Script (Sonic Episode).

The city of Soleanna is ruled by Princess Elise, who is the keeper of a dark secret, the "Flames of Disaster", which involves the Chaos Emeralds. The game opens with the citizens of Soleanna celebrating the Festival of the Sun; while lighting the ceremonial torch, Elise apparently suffers a terrifying hallucination of the city in flames with a demonic creature composed of molten magma in the center. As fireworks are launched, multiple missiles hit the ground around her, and Dr. Eggman arrives with a small army of robots. He reveals his intentions to kidnap Elise in order to obtain the secrets of the Flames of Disaster, who is, of course, unwilling to comply. At that moment, a circle of blue wind appears around them and the blue circle of wind revealed to be Sonic, who destroys a small number of Eggman's robots and escapes with Elise, while Eggman orders his robots to fire on him.

As Sonic escapes, the scene switches to the sight of a white-furred hedgehog named Silver, who speaks of finally locating the "Iblis Trigger". While running through the city, a confused Elise asks Sonic why he is helping her, but he replies that he has "no special reason". Soon afterward, more of Eggman's robots attack them, and Eggman successfully captures Elise in the Egg Mobile while Sonic is distracted fighting them. As Eggman returns to the Egg Carrier, Elise throws Sonic her Chaos Emerald, which he catches and assures her that he will rescue her. Unconcerned, Eggman simply decides to let Sonic hold onto "his" Emerald for the time being, and escapes on board the Egg Carrier as Sonic looks on.

The next morning, while attempting to gather information on Eggman's whereabouts, Sonic runs into Tails, who has apparently been helping to clean up the city after Eggman's attack. Tails reveals that he knows that Sonic had attempted to save Elise, and offers to help Sonic out however he can; while he doesn't know what Eggman's up to this time, he knows it isn't good.

Sonic and Tails chase the Egg Carrier to Wave Ocean, a nearby beach, but are unable to catch up to it before it escapes. Defeated for now, Sonic and Tails decide to return to the city.

Sonic and Tails make their way to the Dusty Desert, where Eggman has been seen, and landing right in the room where he is keeping Elise, who is quite glad to see them (or at least Sonic). At that moment, Eggman arrives and unleashes his Egg Cerberus robot on them, which Sonic defeats. Afterwards, Eggman sends a massive amount of robots after them, and Tails creates a diversion in order to allow Sonic and Elise to escape unnoticed.

After escaping the desert and entering the plains, Sonic comes to a stop. Elise thanks Sonic for his help, but then notices a wound on his arm. Despite Sonic's insistence that he's fine, Elise bandages his arm with a handkerchief. Blaming herself for Sonic getting hurt, Elise apologizes, but Sonic merely tells her to smile, stating that her smile is all he needs to keep him going. While walking through the plains, Elise fills Sonic in about the Flames of Disaster, Solaris (the sun god honored by Soleanna), how they had nearly faced the full force of his anger ten years ago, and how she had lost her father in the incident, and fears what would happen if Eggman makes history repeat itself. Without warning, Sonic grabs Elise's hand and runs through the plains with her. Afterwards, Elise lightens up, and Sonic gives her some useful advice. However, upon their return to the city, Sonic and Elise are attacked by Silver, who claims that Sonic's actions will condemn the world, and they battle.

Sonic initially has the upper hand, but Silver catches him off-guard and psychokinetically throws him into a building, incapacitating him. Silver demands to know how someone as weak as Sonic could destroy the world; Sonic asks what he means, but Silver decides that it doesn't matter, as long as the "Iblis Trigger" is destroyed. However, Eggman capitalizes on Sonic's distraction to kidnap Elise again, and Sonic attempts to run after them, but Silver isn't about to let him run off. Silver knocks him down with his psychokinesis, and is about to deliver the coup de grace when Amy suddenly steps in. Silver somehow knows Amy, and orders her to move, but she isn't about to let him hurt Sonic any more. Sonic takes the opportunity, thanking Amy, and pursues after Eggman.

After a brief encounter with a group of Soleannan soldiers, who accept Sonic's help despite initial reluctance, Sonic enters the warehouse district of New City and meets up with Tails and Knuckles, the latter of whom gives him a holographic message that he received from Eggman. Eggman negotiates a deal; if Sonic comes to the White Acropolis and gives Eggman the Chaos Emerald that Elise had given him earlier, then Eggman will let Elise go without a fight. Though Tails and Knuckles are both positive that Eggman is setting up a trap, Sonic decides to go anyway, planning to "thank" Eggman for telling him Elise's whereabouts.

Sonic, Knuckles, and Tails fight through the White Acropolis and enter the room where Eggman and Elise are. Sonic obediently puts the Chaos Emerald onto a small pedestal, but, unsurprisingly, Eggman double-crosses the trio and activates a force field, trapping Team Sonic within. At that moment, Eggman activates his "Solaris prototype" (the name of which surprises Elise), and Sonic and co. vanish into thin air. The minute they vanish, Eggman assures Elise that Sonic, Tails, and Knuckles are still alive (for now), but have been transported to another time period; however, Eggman does not know where they ended up, as he needs a power that Elise apparently possesses and all seven Chaos Emeralds to fine-tune the machine.

Sonic, Tails and Knuckles encounter Shadow and Rouge, who are also trapped in this future. In order to return to the present, they need to create a rift in time and space, which they figure can be created if Sonic and Shadow use Chaos Control together. While searching for Chaos Emeralds, Sonic, Tails and Knuckles encounter Silver, his friend Blaze, and Mephiles, a dark being who resembles Shadow, tells Silver that Sonic is the one responsible for the future's devastation, and takes them back in time to kill Sonic. Sonic learns from a computer file that Elise was killed when Eggman's battleship exploded two days after the Festival of the Sun. After retrieving a pair of Chaos Emeralds, Sonic and Shadow create the space-time rift, allowing them to return to the present.

Sonic returns for Elise, but is once again attacked by Silver, also allowing Eggman to kidnap Elise yet again. Fortunately, Shadow arrives to confront Silver, allowing Sonic to rescue Elise, and he returns her to her castle in Soleanna. Later, Eggman arrives in his battleship and threatens to destroy Soleanna, and Elise willingly surrenders herself to him to protect her people. Eggman explains to Elise that in order for his plan to take over the world to work, he requires the seven Chaos Emeralds and the dormant power of the Flames of Disaster within Elise to awaken Solaris, allowing him to harness the sun god's power over time.

On his way to rescue Elise, Sonic encounters Silver once more who, instead of attacking him, expresses concern for Elise as well. The two hedgehogs team up, but before they reach the battleship, it malfunctions, crashes and explodes, just as Sonic feared while back at the future. However, Sonic and Silver realize they can use Chaos Control to travel back in time to the previous day, before Eggman's battleship launched. Sonic travels to the past alone and reunites with Elise. Defeating Eggman (who battles Sonic with the Egg Wyvern) one last time, Sonic escapes the exploding battleship with Elise and makes it back to solid ground.

Shadow Episode

 * For the script of this storyline, see Sonic the Hedgehog (2006)/Script (Shadow Episode).

In the events after Shadow the Hedgehog, Shadow appears to have joined GUN. His story opens in the midst of a rescue mission of Rouge the Bat, who was sent to retrieve the "Scepter of Darkness" from Eggman's base at White Acropolis, and has not been heard from since. Shadow invades the base and finds Rouge in the midst of accomplishing her mission. They escape to the site that was formerly the castle of Soleanna's kings where they are confronted by Dr. Eggman, who attempts to retrieve his stolen property. Eggman's robots swoop down to attack, and in the heat of the battle, the Scepter of Darkness is completely shattered. With the seal destroyed, Mephiles is freed.

Resurrected in the likeness of Shadow through his shade, Mephiles the Dark introduces himself and hints at past history that the two shared. Mephiles, using a time warp similar to Chaos Control, flings Shadow and Rouge to a future on the brink of collapse. When they arrive, they are first perplexed, but before long, they find some disturbing answers. Along the way, they find an inactive, dusty E-123 Omega, lying in stand-by mode for hundreds of years for an unknown reason. They discover that they are in the distant future, destroyed by the demon Iblis. Shadow and Rouge meet up with Sonic, Tails, and Knuckles, who were sent to the future by Eggman's latest machine. Sonic and Shadow conclude that they must use Chaos Control to get home, and set out to locate the Chaos Emeralds. After a confrontation with Iblis, they succeed in finding two Chaos Emeralds and successfully create a time warp to the present. Sonic and company go back to their time, except for Shadow, who stays to confront Mephiles. Upon catching up with Mephiles, he reveals to Shadow that the humans, looking for someone to blame for the destruction of the Earth, saw Shadow responsible for the catastrophe. Shadow is hunted down, defeated, and trapped behind an energy seal. Mephiles tempts Shadow to join him to gain vengeance upon the humans, but Shadow refuses, at which point Mephiles transforms into his second form, a more powerful crystalline monster, and the two engage in battle.

Rouge, in the present, realizes that Shadow is alone in the future fighting Mephiles, without a Chaos Emerald. She searches for E-123 Omega, gives him a Chaos Emerald, and tells him to sit and wait in stand-by mode until the distant future becomes the present, and to assist Shadow fighting Mephiles. Shadow, at Mephiles' mercy, is rescued by Omega, who gives him the Chaos Emerald and helps Shadow fight Mephiles. Defeated, Mephiles flees to the present through a time warp and Shadow and Omega follow him to the present. Omega pursues Mephiles, and Shadow finds Rouge, who informs him that Dr. Eggman is apparently searching for him. Shadow concludes that Eggman is searching for Mephiles, and goes to interview the doctor. Upon locating Eggman's base, Eggman tells him that, to understand why he wants Mephiles, Shadow must know about the accident that happened 10 years ago, the Solaris Project.

Shadow then leaves only to find Sonic, who is under attack by Silver. Shadow rescues Sonic, who runs away with Princess Elise, and Shadow engages in a fight with Silver. Shadow is able to overcome him by freezing time so Silver cannot defend himself. Refusing to just be defeated, Silver also induces Chaos Control, to Shadow's shock. Shadow tells Silver that in order to understand more about Mephiles and Iblis, they would have to use the warp and witness the accident themselves. So the two of them, using the Emeralds, open a time warp to 10 years ago, the Solaris Project. They witness the Solaris Project's failure at hand, and watch as Iblis and the original Mephiles, a dark puddle, emerge, opening Silver's eyes to Mephiles' deception. The Duke of Soleanna tells them that the demons must be sealed, so he gives Shadow the Scepter of Darkness. Shadow goes to capture Mephiles, and Silver goes to capture Iblis. It is here that Shadow finds out why Mephiles knows him; it was Shadow who sealed him in the Scepter of Darkness in the first place. With the demons sealed, Shadow leaves the Scepter in the past since he knew where it would end up in the present day. Silver and Shadow return and Shadow rushes off to find Rouge to tell her what he learned about Mephiles. Shadow finds Rouge and tells her to find out what the Scepter of Darkness, Mephiles' seal, was made of, so they can create another one.

Elsewhere, Omega has found Mephiles on the beach and defeats him once again, but Mephiles laughs and tells Omega that the reason he can defeat him so easily is because he was built to defeat Shadow later on. Omega refuses to acknowledge the truth at first but after Mephiles escapes again, he admits to Shadow and Rouge that he was the one that sealed Shadow in the future. Shadow, Omega, and Rouge chase Mephiles to a desert temple with a new Scepter of Darkness, but Mephiles has already found the yellow Chaos Emerald. After Shadow fights him and gains victory, Mephiles reverts back into his original form, a puddle of darkness. Shadow attempts to seal him in the new Scepter of Darkness, but it shatters and Mephiles is able to free himself. Mephiles reveals that what worked ten years ago no longer does because he is using Shadow's form. Mephiles uses his powers to summon a giant clone army of himself and he attempts, once again, to trick Shadow by convincing him that he is a fool for continuing to protect those who will eventually seal him away. In response, Shadow replies, "If the world chooses to become my enemy, I will fight like I always have!" Shadow then removes his gold rings and in a huge burst of energy, defeats the Mephiles clones with his allies by his side and the story ends as a cliffhanger.

Silver Episode

 * For the script of this storyline, see Sonic the Hedgehog (2006)/Script (Silver Episode).

Silver lives approximately 200 years in the future where telekinetic powers are a common ability. In the future, Silver's world is completely destroyed by what is known as the "Flames of Disaster". Fought by Silver and his partner and best friend, Blaze the Cat, this is known as an immortal being known as "Iblis". After Silver becomes frustrated over the fact that Iblis cannot be defeated, a mysterious figure named Mephiles suddenly appears and, along the way, informs Silver of the time when Iblis was first unleashed onto the world. He tells him that Sonic was the main cause of the "Flames of Disaster" and refers to him as the "Iblis Trigger".

Mephiles sends himself along with Silver and Blaze back in time to the point when "the Iblis Trigger was alive" to prevent Sonic from destroying the future. Upon reaching the present day, Silver realizes that he got separated from Mephiles and Blaze and, elsewhere, Blaze makes the same realization. When Silver has his sights finally set on the Iblis Trigger, he is interrupted by Amy, who mistakes him for Sonic. Amy quickly develops a friendship with Silver, and she promises to help him find who he is looking for, not realizing that he plans on finding and killing Sonic. After locating Sonic in the city, Silver engages him in combat and just as Sonic is about to be killed by Silver, he is saved by Amy. While Sonic runs off to find Elise, who was kidnapped by Eggman during the battle, Amy gets upset over the fact that Silver would even suggest that Sonic would destroy the world in the future and she quickly leaves Silver.

Both confused and puzzled when Blaze finds him, Silver questions whether or not he should kill Sonic just for the sake of saving the future. To find more answers, Silver and Blaze journey to Eggman's base. After resolving that he should kill Sonic, Silver finds Mephiles, who tells him that Sonic is at the terminal station. Silver heads there and fights Sonic again, only to have Shadow save Sonic just as Silver was about to finish him off. Silver mistakes Shadow for Mephiles and Shadow corrects him. The two battle it out and actually induce a Chaos Control using the two Chaos Emeralds they have in their possession. They teleport into the past 10 years ago and find out what went wrong. Silver and Shadow arrive at the perfect moment, during the explosion that releases Mephiles and Iblis in the first place and, ultimately, causes the Duke of Soleanna's death.

Shadow seals the original Mephiles in the Scepter of Darkness and Silver learns that to defeat Iblis, they must seal him inside someone's soul, making that person into a sort of vessel. Silver also learns more of Mephiles' intentions and discerns that he lied to him about Sonic being the Iblis Trigger. Upon returning to the present, he meets up with Blaze, shares his findings and has a change of heart, resolving to help Sonic save Elise.

Unfortunately, Sonic, Silver and Blaze arrive too late, as they watch the Egg Carrier explode causing the death of Elise and possibly Eggman as well. Silver then tells Sonic that if they use Chaos Control, Sonic can save Elise. Sonic rushes into the past to save Elise and gives Silver a Chaos Emerald for him to return to the future. After journeying back to the future, resolved to finally defeat Iblis, Silver and Blaze fight Iblis and successfully defeat him. When Silver tries to seal him, though, by using himself as a vessel, Silver is unable to use himself as a vessel to seal Iblis. As the ultimate sacrifice, Blaze uses herself as the vessel, sealing both herself and Iblis into another dimension to save both Silver and her world. Disturbed over the loss of a good friend, Silver becomes upset, unsure if what he had set out to do was worth what he had to pay in the end. Nevertheless, light returns to Silver's world, and the game ends with him glaring at the Chaos Emeralds while Blaze is sealed with Iblis in another dimension.

Last Episode

 * For the script of this storyline, see Sonic the Hedgehog (2006)/Script (Last Episode).

Mephiles is seen sporting an evil look as he finally seems prepared to merge with Iblis and destroy the world. Using his purple Emerald, Mephiles blinds Sonic and Elise, who were continuing their stroll from where Sonic's storyline left off. When they are distracted, he rises from the ground and launches an energy beam that impales Sonic through the back, killing him instantly. Elise frantically attempts to revive Sonic, but upon discovering that he is indeed dead, she cries in despair, releasing Iblis. At this point, Mephiles absorbs Iblis, mutates into a monster known as Solaris and then creates his own world to destroy time itself. Continuing from where Shadow's story ended, he and his friends recover from their battle with the Mephiles clones and Shadow notices the Green and Yellow Chaos Emeralds that Mephiles left behind. These create a blinding flash that send Shadow, Rouge and Omega to the time-space rift formed by Solaris. Meanwhile, in Soleanna, Amy, Tails and Knuckles notice a large bright light that engulfs the city. When the light fades, they realize that they have also been transported to the rift where all of the previous levels in the game exist. Amy is the first to spot Silver, who has been teleported here as well by the Chaos Emeralds that Blaze used to seal Iblis within her. Everyone notices that they have all been brought to this strange place, even Dr. Eggman. As they try to understand what was happening, Dr. Eggman reveals that Iblis' seal has been broken. It is then that they turn and see Elise, cradling Sonic's body in her arms. After a few realizations, Eggman reveals that Solaris is about to bring about the end of the world by destroying time itself, and that, being a transcendental life form, it cannot be defeated in the present as it exists in all timelines, so defeating it in the present would do nothing. Silver refuses to give up, and suggests that they team up and destroy Solaris in the past, present and future all at once, but Shadow quickly shoots that possibility down, stating that, with Sonic dead, Solaris is completely unstoppable.

With Amy upset over Sonic's death and their impending doom, Elise recognizes a familiar wind in the air that makes her come to believe that Sonic may not be entirely dead yet. Silver, furthering Elise's observations, explains that they can use the Chaos Emeralds to revive him. After a lengthy search on the part of Tails, Omega, Knuckles, Silver, Rouge, Amy, and Shadow, they find the Chaos Emeralds and revive Sonic, with Elise's kiss transforming him into Super Sonic. Super Sonic uses his power to transform Shadow and Silver into their Super States. Together, the three hedgehogs fight Solaris, and they manage to destroy Solaris's consciousness. Losing control over his body, Solaris's body diverges into streams of energy, reverting it to its original state: a tiny flame. Sonic, now back to normal, travels with Elise to a point in the past where they find the "flame of hope" and its birth. Elise realizes that if she puts out the Flames, Solaris will never exist, but she and Sonic will never meet each other, which Sonic confirms. Overcome with despair, Elise begins to cry and shouts that she does not care what happens to the world as long as she and Sonic are friends. Though Sonic is clearly unhappy about this as well, he tells Elise to just smile and manages to convince her to abandon their meeting. She confidently puts out the Flames, eliminating Solaris from existence once and for all.

Time reboots back to the Festival of the Sun, only Eggman does not attack this time around; in effect, none of the games events ever actually happened. Elise is in her boat waving the audience as Sonic runs through the public, the "wind" of his speed making Elise lose one of the feathers in her hair. A maid asks her if everything is alright, and Elise says that she thought someone was calling her. Another maid replies that it's just the wind, and Elise says that it might be, but that it felt familiar somehow, and smiles, apparently knowing who it was. She continues with the festival as Sonic watches from a rooftop. The game ends with Sonic watching Elise's feather flying into the night, also smiling.

Excluding the ending cutscene, the events of the game are thus erased from the Sonic the Hedgehog series' timeline.

Playable
There are three fully playable characters in this game, which are progressively unlocked by playing each character's story in the game. The player begins with Sonic; and other playable characters become available when they are encountered, similar to Sonic Adventure, Sonic Advance 2 and Sonic Advance 3.

Supporting
Supporting characters are companions of the main three characters (Sonic, Shadow and Silver) who can help out from time to time in specific levels. When you meet them, you can switch to them and do things with their unique abilities that the main character cannot. Also, every one of them, except Blaze, take part in reviving Sonic in the End of the World level (an interesting fact is Sonic and Shadow's supporting characters were their teams in Sonic Heroes). On an interesting side note, the three main characters also appear as allies in each others levels; Silver is a ally of both Sonic and Shadow in their respective version of Kingdom Valley and Aquatic Base, and Sonic and Shadow are allies of Silver in the latter's version of those same levels.

Miles "Tails" Prower
Tails is the most playable supporting character in this game. Tails can be considered the fourth main playable character because he has access to places that Sonic, Shadow and Silver have like being playable in the Adventure Field (Town Stage), having his own character select screen in the main menu and being playable in 10 places, which most are his own levels (Wave Ocean twice, White Acropolis, Crisis City, Kingdom Valley, Radical Train, Adventure Field-Soleanna Castle Town, Mission: The Three Musketeers, Aquatic Base, End of the World). Sonic's best friend, and an inventor nearly on par with Dr. Eggman. Tails can use his two tails to fly and reach things that Sonic can't, such as hitting a switch to open a door. Tails can also fly through Dash Rings that appear in some stages (as was the case in Sonic Adventure, Sonic Heroes, and Sonic Riders). He can also throw a "dummy ring bomb" that can destroy an enemy, similar to his ability from Sonic Heroes. His flight ability can be drastically extended by releasing /before reaching max height and then holding /for about 2 seconds after he begins descending. However, he still lacks overall speed compared to other supporting characters.

Playable In: Wave Ocean (twice), White Acropolis, Adventure Field-Soleanna Castle Town, Mission: The Three Musketeers, Aquatic Base, Crisis City (End of the World & DLC), Radical Train (DLC), Kingdom Valley (DLC)

Knuckles the Echidna
Knuckles is a powerful echidna with a bad temper, and he's quick to use his fists to solve any problem. Usually found guarding the Master Emerald on Angel Island, he's always willing to help Sonic thwart Dr. Eggman's latest scheme. Knuckles is able to glide and has an attack called Screwdriver, which is very similar to the Maximum Heat Knuckles Attack, but can flatten enemies in succession at average speed. He can also perform a move called Ground Shaker similar to the Hammer Punch, except he is enveloped in an extra fiery aura that paralyzes every enemy in the vicinity upon impacting the ground.

A very common glitch sometimes causes him to get stuck on walls while Climbing. Another glitch allows him to complete Flame Core. This is the only way to see his victory pose on the Results screen, since he is the only character that does not finish a stage under normal circumstances.

Playable In: Flame Core, Mission: The Three Musketeers, Aquatic Base, Tropical Jungle (End of the World)

Rouge the Bat
An elusive jewel thief who also happens to be a valued government spy. Rouge journeyed to Dr. Eggman's base, White Acropolis, in search of the "Scepter of Darkness" for G.U.N, but never returned. After receiving a briefing from the government, Shadow is introduced into the storyline as he sets out to find and rescue her. Rouge has the ability to make round bomb-like objects and throw them at enemies, similar to her Bat Cracker ability from Sonic Battle. She can also glide, climb and put bombs on the walls she is climbing on, or throws bombs to attack and gain height. She also has Knuckles' climbing glitch. She has the most compulsory missions in the game out of all the supporting characters.

Playable In: White Acropolis, Kingdom Valley, Flame Core, Tropical Jungle, Wave Ocean (End of the World), Crisis City (Very Hard DLC), Radical Train (Very Hard DLC), Aquatic Base (Very Hard DLC), Dusty Desert (Very Hard DLC)

E-123 Omega
Omega is the pinnacle of the E-Series robots; he seeks revenge on Dr. Eggman for imprisoning him inside of his base. Like in Sonic Heroes and Shadow the Hedgehog, he is, once again, an ally of Shadow, helping him confront the mysterious Mephiles. Unbeknownst to him, Omega has a pivotal role in Shadow's storyline and the events that unfold in the future. Omega has the abilities to both hover and shoot rapid-fire. He meets up with Rouge at the end of the Tropical Jungle stage. His hover ability can be exploited to fly without descending by tapping the / repeatedly rather than holding it. He has also gained an increase in speed that makes him the second-fastest supporting character (behind Blaze), a change in design and a new voice actor.

Playable in: Boss: Mephiles, Wave Ocean, Dusty Desert (Twice with DLCs), Flame Core (End of the World & Very Hard DLC), White Acropolis (DLC), Kingdom Valley (Very Hard DLC), Radical Train (Very Hard DLC), Aquatic Base (Very Hard DLC)

Blaze the Cat
Blaze is a character who plays a very pivotal role in Silver's story. Previously appearing in the game Sonic Rush, she is a princess from another world who has the power to control fire. She is very calm and introspective, a personality befitting of her rank. However, she keeps her anger bottled up inside of her, and can be very stubborn at times. She is described as a combination of Sonic and Knuckles. Her homeworld is the same as Silver's and the two share a brother-sister relationship. Both she and Silver have tried to destroy Iblis in the future, but have never succeeded. Like Tails' Extra Mission, she does the Wave Ocean stage completely on her own. Blaze is considered by fans to be the most Sonic-like supporting character in the game because of her using the Fire Claw move like the Homing Attack.

In gameplay, Blaze is Silver's counterpart to Sonic and Shadow, possessing speed equal to both of them. She can do the Fire Claw to home onto and attack enemies, the Accelerator Tornado for both offensive and gaining altitude, and the Spinning Claw where she makes up a vortex of flames for ground- and midair offense.

In character introduction document from March 2006 Blaze is described as "Tsundere type". She wears a "Takarazuka-like costume" under her cape.

Playable In: Crisis City, Wave Ocean, White Acropolis (Twice with Very Hard DLC), Tropical Jungle (DLC), Aquatic Base (DLC).

Amy Rose
The self-proclaimed girlfriend of Sonic. She has a keen sense of intuition, and a fearless personality. The first time Amy meets Silver, she mistakes him for Sonic, similar to an event in Sonic Adventure 2 when she mistook Shadow for Sonic. The two end up teaming up to go on a search for the people they are looking for, unaware they're both looking for Sonic. Amy also has a connection with Elise, once Amy rescues her and gives her love advice. She can double jump, use her Piko Piko Hammer to whack enemies, and can turn invisible to sneak up on enemies. Also, she is playable in a Town Mission protecting Elise from robots, after beating the White Acropolis stage. Amy is the least playable character in the game likely due to leaving Silver after he made an attempt on Sonic's life.

In character introduction document from March 2006 Amy is described as "An obsessively trend-conscious teenager".

Playable In: Dusty Desert, Town Mission: Protect the Princess, White Acropolis (End of the World)

Non-playable

 * Princess Elise - The princess of Soleanna, a kingdom where the Sun God Solaris is worshiped, who harbors a dangerous secret. Ten years ago, the demon force, Iblis, was sealed away in her body by her father at the age of seven. The key to this seal is her own despair, which will release the form inside her. Her father, in order to protect her, urged her, shortly before his death to remain strong and never let herself cry, no matter what. Ten years later, she is a noble young princess of the age of 17. On one side, she is a prim and proper princess, but on the other, she is a confused and anxious girl. She tries to make light of her fate, but her encounter with Sonic is what shall truly set her soul free. Having stopped the destructive "Flames of Disaster" ten years prior to the start of the game, only she knows the secret of the "Flames of Disaster" and its relation to the Chaos Emeralds. Interestingly, the Chaos Emerald in her possession was originally green, but it has been changed to blue in the final game, and her voice is different in the original trailers. Although not technically playable, Sonic carries her in the Dusty Desert and Tropical Jungle stages. Sonic still plays the same (though he is unable to use the Spin Dash or his gem-granted abilities), and he gains a new ability. By combining their powers, they can form a shield which will let them float on quicksand or deep water, which would otherwise engulf them. It is not to be confused with the traditional shields from Sonic games (which do not appear in the game, despite a shield powerup being mentioned in the manual), Sonic will still lose rings (or die) when attacked.
 * Duke of Soleanna - Elise's father, the ruler of Soleanna. When the Solaris Project failed, the world-destroying power of Iblis and Mephiles was released. Despite being gravely wounded, he was able to bind Iblis by using his daughter, Elise, as a "vessel" body. By so doing, he was able to save the world from imminent destruction, even as he drew his last breath. He was a brilliant scientist. He also had a strong sense of patriotic and kingly duty, and loved and trusted his daughter dearly. Before he died, he told Elise never to cry, as unlocking Iblis is in Elise's tears and despair. However, since Elise blew out the flame that was Solaris, thus erasing him from existence, "Project Solaris" never occurred, which could suggest that Duke of Soleanna may have died from another cause, or he may never have died at all.
 * Dr. Eggman - Sonic's archenemy, his main goal is to conquer the world. In Sonic's story. He is after the power of the "Flames of Disaster", and knows about Princess Elise's mysterious power. He hopes to use the "Flames of Disaster" secret to rule the world and control time in the past, present, and, future. His appearance has noticeably changed from the style established in Sonic Adventure; he still wears his red, gold, and black Sonic Adventure attire, but no longer wears goggles as a headband, has lost most of his trademark weight (though a gut is still clearly visible under his shirt), and wears dark sunglasses with a built-in radar that can apparently detect the Chaos Emeralds. If one looks closely at him during cutscenes featuring him while the camera is viewing him from the side, he appears to have blue eyes. In the character introduction document he is described as "romanticist and womanizer".
 * Solaris - The final boss of the game; the monster that Mephiles transforms into after absorbing Iblis, Solaris is the sun god of Soleanna. Contradictorily known as the Flame of Hope, it is said that the rage of Solaris will destroy the world.
 * Mephiles the Dark - The main antagonist of the game. A creature of the mind, the will of Solaris. In order to absorb with Iblis, to "return" to his true form, Solaris, his goal is to break Elise's seal. He manipulates Silver throughout his story. He is the one who informs Silver that Sonic releases Iblis, referring to him as the "Iblis Trigger". He assures Silver that he must kill Sonic in order to rectify his future and save his home world. In Shadow's storyline, although harboring resentment for sealing him in the past, Mephiles tries to entice and persuade Shadow into joining him to destroy the world and gain retribution on mankind for capturing and sealing him in the future. Nevertheless, his methods fail to corrupt Shadow. He appears to have three forms: the first form is the original: a dark puddle-like, or gaseous form. The second form, whereby he has brighter skin, this is his powered up form; the third and form being, whereby he sports darker skin - this is the form he took from Shadow.
 * Iblis - The monster called the Flames of Disaster is the secondary villain of the game and the main villain of Silver's story: it is the raw power of Solaris. Iblis appears to be a mindless destructive creature made of flames. It was sealed within Elise after it was separated from its other half of Solaris, Mephiles. Eventually Iblis was freed and wrecked havoc for hundreds of years until Silver's time. It was sealed within Blaze before she disappeared.

Cast
This game features the 4Kids Entertainment cast from Sonic X in the English version while the Japanese version has mostly the same seiyū from Sonic X and the game series.

While there is no option in game to switch voices, the bios on both systems can be changed to the Japanese language to enable the Japanese voices. However, the entire game will be in Japanese, with no option to switch subtitles.

In addition to the 4Kids actors in the English version, Lacey Chabert, who is coincidentally a long-time Sonic fan, voices Princess Elise, marking the first time in the history of the franchise that Hollywood talent has provided voice-over work for a Sonic game.

The following voice actors have appeared in this game:

Gameplay
Although each character plays the same levels, each character's unique abilities allow him or her to get to different areas of each stage, and deny them from accessing certain items. Levels are far less linear than previous 3D Sonic titles, offering up many alternate pathways through each stage. Certain areas in each of the levels, dubbed "Mach Speed Sections", allow Sonic to reach speeds that would be unattainable elsewhere, though at the cost of always moving forwards without being able to stop.

Gameplay is broken up into two gameplay styles, similar to Sonic Adventure: Action Stage and Town Stage. Action Stages are primarily where the bulk of the gameplay takes place, whereas Town Stages are free-roaming locations where the player can talk to non-player characters and explore, similar to Sonic Adventure ' s Adventure Fields.

For each of the action stages in the respective stories, gold medals are obtainable by achieving S rank in these stages or completing it (Both in Normal and Hard mode), or by obtaining all 10 Silver Medals on the stage, giving a total of 5 Gold Medals per stage.

The ranking system in the game for each of the levels and the town missions is similar to Sonic Rush, providing score ranks with the highest rank being S while the lowest rank is D, unlike previous Sonic games where the lowest was E and the highest was A.

Town Stages
The game takes place exclusively within the City of Soleanna and surrounding area. In town stages, you can talk to NPCs, take Town Missions, buy Level Up Items using rings collected through Action Stages or Town Missions, and further the game's plot by finding entrances to Action Stages. There are three sections to Soleanna: Castle Town, Soleanna Forest and New City

Town Missions
NPCs appearing in Town Stages with a blue exclamation point hovering over their head will provide you with missions to complete for additional rings. Missions are usually completed as a single character of your team, generally the main character of the story, though missions do exist where you play as more than one character. Sometimes, Town Missions will begin as a logical progression of the plot, such as Eggman's robots attacking the citizens of Soleanna - leaving you with the task of defeating all the robots. In order to get an S rank on missions, 30,000 points are needed, as opposed to 50,000 in action stages. In one mission in New City called "The Legend of the Three Musketeers", upon finishing it you get a ring (similar to the one Sonic gets in Sonic Unleashed at the end of the Dark Gaia battle). It's not confirmed what the ring does or what it is for.

Action Stages
The Action Stages are the regular playable levels in the Game.


 * 1) Wave Ocean
 * 2) Dusty Desert
 * 3) White Acropolis
 * 4) Crisis City
 * 5) Flame Core
 * 6) Radical Train
 * 7) Tropical Jungle
 * 8) Kingdom Valley
 * 9) Aquatic Base
 * 10) End of the World

Multiplayer
Sonic the Hedgehog features two styles of multiplayer gameplay that offer two-player action. In both modes, the Level-Up Items the three characters can use are limited to how many of them have been collected in the story mode. The game was originally supposed to be 4 player, but was changed due to deadlines for completing the game. Shared features between the two modes are downgraded graphics, making objects and enemies shaded. Several auras from the character animations are also removed here, including the Homing Attack's aura, Shadow's hand auras while charging a Chaos Spear/Chaos Lance, and Silver's psychic moves. It should also be noted that some of the characters' movements have been fixed or altered; the flawed Light Speed Dash operates perfectly in multiplayer, and Silver has gained the ability to grind; he is faster than Sonic and Shadow in grinding, but lacks proper Crouching. High Speed items also make more frequent appearances in the multiplayer than in Action Stages, and the Invincibility sparks work for every character, not only Sonic. This all seems to lie in the fact that not all the Stages' layouts and have been incorporated into multiplayer mode, as evident by the incomplete areas seen when the player glitches out of the normal stage boundaries. Furthermore, Tropical Jungle and Radical Train are not used in the multiplayer.

The first mode, Tag Mode, is a co-op type of play between Sonic, Silver and Shadow. Two players, each one controlling a character, must work together to clear levels and collect Chaos Emeralds. Lives are shared in this mode, so if one player loses a life when only one life remains, both will receive a game over.

The second game style available is Battle Mode. Battle mode pits two players against each other and has them race to a goal in the selected level. The player who reaches the goal first is the winner. In this mode, there is no score total or a system of losing lives.

The previously rumored mini-games that were to allow up to four players to play simultaneously/alternately (Quiz, Race and a few others) seem to be missing in the final release of the game. The U.S. manual and Sega America game site (did prior to release of the game) do not mention any other modes other than the aforementioned Tag and Battle modes. It is also possible (and somewhat likely) that these minigames were moved to the Wii's Sonic and the Secret Rings, which sports a 4-player minigame mode with Sonic, Shadow, Silver and other playable characters.

Very Hard Mode
This download has to be purchased separately for each character, 'Very Hard Mode' consists of more enemies, being forced to take the hard paths and even going through levels backwards; amigos also get a bigger role in this than in normal gameplay (most notable in Shadow's levels, where Rouge and Omega are in every level except Wave Ocean). Each main character's missions must be purchased separately for $2.49 each.

Team Attack Amigo
This download includes an Extra Stage where the player must pass through eight different parts of the stage. The first three parts are played by Miles 'Tails' Prower as the player must go through Crisis City, Radical Train, and Kingdom Valley. The 4th and 5th parts are played by Blaze the Cat where the player must go through Tropical Jungle and Aquatic Base. The 6th and 7th parts are played by E-123 Omega where the player must go through Dusty Desert and White Acropolis. The final part of the stage consists of a boss fight where the player must fight the Egg Genesis as Omega to beat the Stage.

This download is available on both the Xbox 360 and PlayStation 3 Japanese and European versions, and the North American Xbox 360 version but the North American PS3 version doesn't offer the download.

The European Xbox 360 version of the DLC doesn't save any of the stats after finishing the stage.

Boss Attack
Boss Attack has to be bought separately for each of the characters. Boss Attack is similar to the boss attack mode in Sonic Adventure 2, and a similar boss from Sonic Heroes is brought back where as the player has to fight several waves of enemies. The player has to defeat all bosses from the corresponding storyline and nearly each of them is slightly more difficult than the original fight (there are extra enemies in the boss arena, the boss attacks more frequently and attacks in bigger variety). Defeating all of the bosses isn't the only objective however. Between boss battles, the player must defeat all the enemies that spawn in sub-arenas which are altered versions of boss arenas or hub worlds.

Achievements
These are the achievements which add to the player's Gamerscore on the Xbox 360 version of Sonic the Hedgehog (2006).

Music
The main theme for the game, entitled "His World" performed by Ali Tabatabaee & Matty Lewis from Zebrahead.

Hip-hop/R&B performer Akon has done a remix to Dreams Come True song "Sweet Sweet Sweet" in Japanese and "Sweet Dreams" in English, which was originally the ending theme for Sonic the Hedgehog 2 for the Sega Mega Drive. The song is entitled "SWEET SWEET SWEET -06 AKON MIX-", in Japanese and "SWEET DREAMS -06 AKON MIX-" in English. It is Sonic's ending theme for the game. More information is available on the Japanese site ; it was also recently featured in a trailer from the Tokyo Game Show. Both versions are available to listen in the game, but are omitted in both Soundtrack releases of the game.

Crush 40, who have done several songs for the Sonic series in the past, performed a cover of "All Hail Shadow", one of the vocal songs from the Shadow the Hedgehog soundtrack, originally sung by the band Magna-Fi. However, aside from this one track and 2 others, Jun Senoue did not compose the music for this game.

Silver's theme, "Dreams of an Absolution" by Lee Brotherton (Remix Factory), can be heard at their website in the "Solo Projects" section of the "Music" header, as well as an exclusive remix of the song. 

Singer/songwriter Donna DeLory performs Elise's theme, entitled "My Destiny".

The in-game music is composed by Tomoya Ohtani.

The soundtrack to Sonic the Hedgehog is available to buy from Sega Direct, under the name Sonic the Hedgehog Original Soundtrack. It was released on 10 January 2007. There are two different albums: the OST and the vocal album Sonic the Hedgehog Vocal Traxx: Several Wills. The Vocal Trax is on one disc while the OST is on three discs.

Reception
Sonic the Hedgehog was generally panned by critics and became one of the most notable video games for its negative reception. While many believe this was becuase of a rushed development cycle, that was only one of many issues the game possessed. Many complaints appeared to stem from the game's control, level design, convoluted plot and abundant load times (each lasting around 20 seconds). Another common complaint was with the apparent romance between Sonic and Elise. Receiving low mixes and severe negatives, this game has been so far to be called the "rock bottom of the franchise." Across 39 reviews, GameRankings recorded the average score as 46%; the second poorest average for an Xbox 360 title at the time of the game's release. The later PS3 release received a similar score of 43%.

A number of video game magazines or ranking sites gave the game mixed to negative scores. Famitsu gave a score of 29/40. GameSpot gave the Xbox 360 version a 4.4 and the PS3 version a 4.2. Dave Halverson of Play Magazine was notable for initially giving the game its biggest praise: a score of 9.5 for the 360 version. This was dropped down to 8.5 in the next issue, with Halverson explaining how he was incorrectly told that the load times and glitches in his review copy would not be in the finished product. Later, Halverson gave the PS3 version a 5.5, expressing his disgust for how the glitches and load times had still not improved and how the game now ran even worse despite the extra development time. In the Play Magazine awards of 2007, he stated he would pay praise and honor to the Xbox 360 version of the game, but not the PS3 iteration. As a contrast to its scathing reviews, it was praised for its music.

Sales
Despite all the contemptuous commentary, Sega's official statement according to financial reports on Sonic the Hedgehog regarding its sales were positive, calling them "strong" and seeing the game's commercial performance as "solid", particularly in the United States and Europe, meeting the company's expectations for an overall figure of 870.000 copies sold in the aforementioned regions by May 2007. The game also made it onto the Xbox 360's Platinum Family Hits line, but it was not included on the PlayStation 3's Greatest Hits line, although it met the criteria to qualify in that selection. Other sources have also calculated an estimate of the game's overall sales worldwide, with results giving Sonic the Hedgehog more than 2 millon units sold.

Trivia

 * There are differences between the Xbox 360 version and the PlayStation 3 version. The Xbox 360 version has a few graphical effects that are missing in the PlayStation 3 version. The PlayStation 3 version runs slightly faster, but this comes at a price with less stable framerate and the lack of trophy support due to the system's limitations at the time. Also, the frame rate for the in-game cutscenes, including the boss intro and outro scenes, are locked at 30 FPS on PlayStation 3 in comparision to an unlocked frame rate of 60 FPS on Xbox 360. Plus, some slowdowns for certain parts of the game, like the results background in Crisis City as Sonic for example, have been removed in the PlayStation 3 version. There are a few other minor changes, such as the start of Silver's rival boss battle against Sonic (he starts on the end facing the altar of light across the strip of water in the Xbox 360 version, whereas in the PS3 version he faces the building).
 * Not counting ports, this game is the only Sonic game that is originally designed for the Xbox 360 to run at full 60 FPS, though there are some slow-downs in some portions of the stages and cutscenes.
 * In both modes of multiplayer, the player whose character is Silver can use Psychokinesis on the other player's character.
 * There is a clever wordplay involving Blaze the Cat's choice of words present in the Japanese dialogue. The Japanese word for the color "blue" (adjective) is "aoi" (青い), and the Japanese word for the adjective "naive" is also "aoi" (青い or 蒼い). So, Blaze's mentioning of "Blue Hedgehog..." is "Aoi Hedgehog..." in Japanese, which can be taken either way. This phrase could not be directly translated, so it is missing from the localized version.
 * In the Town Stage of Empire City in Sonic Unleashed, one of the citizens reads a newspaper that features the front cover of Sonic the Hedgehog (2006).
 * There are slight differences in how Silver first caught sight of Sonic. In Sonic's story, he first spots Sonic while he and Elise are outrunning missiles from Eggman's robots and then determinedly clenches his fist and mutters, "I've finally found him... the Iblis Trigger." However, from Silver's point of view, this scene and his statement occurred shortly after Eggman captured Elise and while Sonic was looking up at the Egg Carrier while it flew away. He also raises a different hand both times.
 * Screenshots of the game showed that Sonic's Tropical Jungle was supposed to be a regular level, but it turned out to be an "Princess Stage" in the game's final release.
 * This is the first main console Sonic game to use the S rank.
 * This is the first main console Sonic game for the Xbox 360 and the PlayStation 3.
 * Sonic the Hedgehog (2006) could be the first Sonic game with official russian translation, according to SONICNEXT_allscript file.
 * An advert on the back cover of the Sonic Riders instruction manual says it was due for release on PC DVD-ROM and Xbox 360. The PC version was cancelled and a PS3 version was added later in development.
 * In Silver's Story, when Mephiles is explaining to Silver and Blaze about how to save their world, if one looks closely behind Silver, he/she can notice that there are "SEGA" logos on the posters behind him.
 * Some missions in Shadow's story seem to have an error in reacting with Shadow's storyline: at least two Town Missions haveIblis-and Mephiles-themed minions before the latter was released from the Scepter of Darkness.
 * When Sonic, Tails and Knuckles return to the present and read the newspaper, the title of the newspaper says "Daily Soreana".
 * The credits music for Sonic (Sweet Dreams AKON Mix) is the same tune as the ending theme in Sonic the Hedgehog 2 (where Tails flies the Tornado to save Sonic from crashing into the planet).
 * The game was available for Xbox Games in Demand in 2009, but it was removed the following year as well as the downloadable demo. According to Sega, this was done to increase the value in the franchise.
 * Sonic and Shadow are never playable in each others' episode (Silver and Shadow in Aquatic Base, Sonic and Silver in Kingdom Valley) despite going through the same parts of Flame Core at the same time.
 * In the game's files however, there are voice clips of Sonic and Shadow working together. Animations of Sonic driving a car were recovered from the files as well, however, these findings are rather glitchy.
 * Silver also appears as a rival in every story, except for the Final Story.
 * When Rouge returns from the future, she receives a call from a G.U.N. agent questioning her. In the dialogue, he questions if she has the Book of Darkness, but in the subtitles, it shows that he should have said the Scepter of Darkness. This is most likely a recording error.
 * Another recording error is heard when a G.U.N. soldier is telling Shadow that Omega has gone to Wave Ocean. Near the end of the line, the voice actor can be heard messing up his line, and reading it again.
 * Wmplayer 2017-03-30 16-59-10-331.png "Leaving the Scepter of Darkness" cutscene of Shadow's story, Silver has the Chaos Emerald visible in his hand while jumping at the portal that leads to the present timeline, however, he is supposed to leave it beside the young Elise in the "The Talisman" cutscene of his story. This is most likely an oversight on the developer's part, given that the part with Silver leaving the emerald is unrelated to Shadow's story and was not included in it, the model of the [[Chaos Emerald]] ended up sticking to his hand because he did not place the emerald in the said cutscene.
 * The dialogue of the Last Story's "Embers of Solaris" cutscene differs between the English and Japanese version. In the English version, Elise asks if Sonic has destroyed Solaris, to which he replies that he did not, followed by him saying that the light approaching them is the true Solaris. In the Japanese version, Elise questions if it is over. Sonic replies with 'No", and comments that the light that is approaching them is "Solaris's spark".
 * If one was to compare the information given from the official guide for the game, to the gameplay itself, several interesting points can be gathered:
 * Some screenshots in the guide has Sonic's icon for the life count of every character besides Sonic himself.
 * The guide mentions that E-123 Omega's Hover ability and Tails's Fly are bound to the energy of the Action Gauge along with screenshots that show the said gauge being used by these characters. This, however, is not the case in the final version since the Action Gauge is not displayed during the sections they are playable in. The three hedgehogs are the only characters to have Action Gauges and Omega's hovering only lasts longer.
 * The Silver medals' placements sometimes differ from the game.
 * The guide documents the unused Speed Chip upgrade for Silver.
 * Several Level Up Item and Gems have their details contradict what is up in the game: the Mach Speed would work the same way as what is now the Sonic Boost; the Dummy Ring Bomb would throw an empty item box; and the Teleport Dash could have warped through an enemy and its attacks.
 * Sonic Team originally planned releasing a port of the game as the first Sonic game for the Wii. However, such a port would have taken a long time to create, and Sega wanted to release a Sonic game much closer to the Wii's launch. This became the 2007 video game Sonic and the Secret Rings.
 * According to Sonic Cult, the supporting characters were planned to have episodes of their own, and Metal Sonic would have been playable. This did not happen, possibly since the game was rushed.
 * This is the second Sonic game with an E10+ rating. The first one was Shadow the Hedgehog.
 * According to G4, the game had E rating at some point.
 * At the time, Sonic's voice actor Jason Griffith revealed at Sonicon in November 2010 that 4Kids and SEGA had brought in the Japanese voice directors of the game to direct the English voice cast along with the English directors.
 * Like Sonic Adventure, when the player reaches a certain point in the level and messes up, if he or she tries to restart the entire level it will not work because restarting will either take them back to the previous checkpoint or the start of another part of the current level.
 * An unused gameplay mechanic where Sonic's top speed would have dramatically increased the more Rings he collects can be seen in the E3 2006 beta demo at Sonic Cult. Since the game was rushed, however, this mechanic was never fully implemented, and Sonic's top speed outside of the Mach Speed Stages became slower.
 * This is the first Sonic game to feature HD graphics.
 * This is the first 3D main canon game where the Tornado does not make an appearance.
 * This is the second main series Sonic game released on an important Sonic anniversary year, the other game is Sonic Adventure 2.
 * Excluding the Xbox Live Arcade Sonic games, this game has the least number of achievements (23).
 * It can be noted that Silver is the only character who is playable throughout all four Episodes. He has his own Episode: he is playable in Kingdom Valley in Sonic's Episode, he is playable in Aquatic Base in Shadow's Episode, and he is playable in Dusty Desert in the End of the World level in the Last Episode. He is also playable in his Super State in the Solaris Boss Stage.
 * This is the second game to have hidden items to collect in the Town Stage, the first being Sonic Adventure.
 * It is possible to reach areas with a character that the developers did not intend for that character to reach. For example, you can enter the area right before the end of Silver's first section of Aquatic Base as Shadow, using a glitch that allows Shadow to go through walls. Not only can you explore this area, but Silver's voice clips play when you are Shadow as you enter the last room of the first section. Almost every character can achieve a trick like this.
 * Almost all of the previously showcased beta animations of Sonic (from the off-screen footage of TGS 2005 and E3 2006) were left in the final release, but the only way they can be used is through editing the game's files. The beta Homing Attack animations however are available with the use of the White Gem.
 * The game manual states some features and items that are not in the actual game (due to rushed completion), such as two options for Tag Mode: Tag Story (begin a new game or continue a previously saved game) and Tag Trial (play stages beaten in Tag Story), shields, the Action Gauge limiting the power of Sonic's abilities (and the flying and hovering abilities of Tails and Omega), and the ability to upgrade Custom Actions up to level 3.
 * There's a typo in the ending, when Elise says, "It felt like... someone was calling me," the subtitles read, "It felt like... like someone was calling me."
 * There is a glitch found in Shadow's story that happens when one is to enter New City at the time in-game when they are supposed to enter Dusty Desert through using Shadow's wall glitch at the gate leading to New City. Things like unused mirrors for Flame Core and Crisis City were found. The most interesting thing to be found though, was an entire unused mission. A warp is placed around the area with the mirrors. The mission is fully functional, and even has some unused text after it is completed. However, this mission isn't saved in the Town Trial levels and cannot be accessed with the same save file if you save after completing it.
 * There was a planned combination move between Silver and Blaze that by using the /, the player can use Blaze's pyrokinesis to wrap into flames/approach sides in Iblis' third phase.
 * There was also another combo that Silver can pick up Blaze and throw her to launch a powerful attack in the same boss battle.
 * Amy is the only hedgehog in this game not to fight a boss, have her own episode, or Level Up Items.
 * Silver's story is the only story in which all hedgehogs are playable.
 * Shadow is the only character to fight Iblis, Mephiles, and Solaris.
 * In the achievement, "Blue Phantom," the description mentions Super Sonic. It may reference that when the game was being developed, when Sonic collected all the Level Up Items, the rainbow gem may have been automatically given to the player without needing to buy it, thus allowing him/her to transform into Super Sonic. However, it was scrapped from the game.
 * Some achievements in this game are poorly described. One example includes "Nights of Kronos," in which it tells the player that he/she can see a completely different version of the game's ending in the Last Episode. However, the player gets this achievement when he/she gets an S-rank on both End of the World and Solaris. Another example are the achievements "Silver Medalist" and "Gold Medalist." The description indicates that the player will unlock something when they collect all the silver medals and gold medals respectively, when in reality, they do not. However, it suggests that it was intended for the player to unlock something, potentially Free Mode, but was scrapped as well. "Legend of Soleanna" is unlocked after achieving an S-rank on all act missions, town missions, and boss battles with every character, but its description simply tells the player to "overcome all trials and accomplish a great feat."
 * This is the first time that Shadow the Hedgehog removes his gold rings in the game series.
 * There exists a major glitch that can cause the game to send the player straight to the credits, skipping whatever has not been completed, dubbed the . Performing this credits warp will cause the game to treat your data file as having 100% for that episode. However, doing so will also skip any missions, acts, and bosses that haven't been completed. Meaning, that if Shadow hasn't been unlocked yet, he cannot be unlocked for that save file.
 * If the player removes the game disc while the game is still playing on the PS3 version, it will just continue playing as if the disc was still inside. However, the music will stop playing.
 * This is the first main series game where Sonic and Shadow do not fight each other in Story Mode.
 * In the Family Guy episode "The New Adventures of Old Tom", some video game cases can be seen in the background, with one of them resembling Sonic the Hedgehog (2006).
 * Even though both the "Running through the plains" and "Knuckles delivers a letter from Eggman" cutscenes, along with the title screen video, are pre-rendered and set to work at 30 FPS, they do not use the CGI graphics of the game.
 * This game was originally going to have a day and night feature, but the idea was scrapped for time restraints and the concept was later used in Sonic Unleashed instead.
 * Sonic the Hedgehog (2006) is the first main game to have all four hedgehog main characters presented (Sonic, Amy, Shadow, and Silver). The others being Sonic Generations and Sonic Forces.
 * Of these games, Sonic the Hedgehog is the only one to have all four of them playable.
 * All of these games are also anniversary titles.
 * Shiro Maekawa had written a draft for the game's story that would have connected it more clearly with Sonic Rush.

Similarities to Sonic Adventure

 * 1) Adventure Fields were used in the game.
 * 2) There were multiple playable characters in the game, each with special abilities, and sharing one story from each perspective of it.
 * 3) The Egg Carrier reappeared in the game, although it seems to have been rebuilt and had a much sleeker look than before.
 * 4) A female character was kidnapped by Eggman in both games. (Sonic Adventure - Amy; Sonic the Hedgehog- Elise).
 * 5) A character died on-screen (Sonic Adventure - E-102 Gamma; Sonic the Hedgehog - Sonic and the Duke of Soleanna)
 * 6) A female character was floating and then vanished to another world to seal away a monster. (Sonic Adventure - Tikal; Sonic the Hedgehog - Blaze)
 * 7) A terrifying monster was used in the game. (Sonic Adventure - Perfect Chaos; Sonic the Hedgehog - Iblis)
 * 8) Treasure hunting was used for levels. (Sonic Adventure - Knuckles; Sonic the Hedgehog - Rouge)
 * 9) Sonic used a snowboard at a snow-themed level. In addition, a snowball also chased Sonic in the levels. (Sonic Adventure - Icecap; Sonic the Hedgehog - White Acropolis)
 * 10) A character's lips kept moving once in a while even after they finished their lines.
 * 11) It had Amy as a solo playable character in a 3D Sonic game.
 * 12) It had an E-Series Robot as a solo playable character. (Sonic Adventure - Gamma; Sonic the Hedgehog - Omega)
 * 13) It had a purple cat character who's name starts with "B" as a solo playable character. (Sonic Adventure - Big; Sonic the Hedgehog - Blaze)
 * 14) It had one playable character to never appear nor be mentioned in the last story. (Sonic Adventure - Gamma, however the Flicky that emerged from Gamma's body is seen next to Amy which represents him in spirit; Sonic the Hedgehog - Blaze)
 * 15) It had a creature in liquid-like form. (Sonic Adventure - Chaos; Sonic the Hedgehog - Mephiles)
 * 16) They had places that were flooded. (Sonic Adventure - Water; Sonic the Hedgehog - Lava/Flames)
 * 17) A character was sacrificed to save the word. (Sonic Adventure - Tikal; Sonic The Hedgehog - Blaze)
 * 18) They had similar final boss fights in Sonic's story. (Sonic Adventure - Egg Viper; Sonic the Hedgehog - Egg Wyvern)
 * 19) Two creatures were sealed by someone with a crystal item. (Sonic Adventure - Tikal and Chaos; Sonic the Hedgehog - Shadow and Duke)
 * 20) A person traveled through time with someone. (Sonic Adventure - Tikal; Sonic the Hedgehog - Mephiles)
 * 21) A boss fight involved a giant robot with weapons. (Sonic Adventure - E-105 Zeta; Sonic the Hedgehog - Egg Genesis)
 * 22) An Egg Carrier launched from Eggman's base. In addition they were also the last levels of Sonic's story. (Sonic Adventure - Final Egg; Sonic the Hedgehog - Aquatic Base)
 * 23) They have a city that has been ruined and destroyed. (Sonic Adventure - Station Square; Sonic the Hedgehog - Crisis City)
 * 24) The first levels of Sonic's stories were beaches. In addition, an orca chased Sonic at during the stage (Sonic Adventure - Emerald Coast; Sonic the Hedgehog - Wave Ocean)
 * 25) Both games have a level featured around a volcano. (Sonic Adventure - Red Mountain; Sonic the Hedgehog - Flame Core)
 * 26) Both games have different soundtracks at some point during an action stage.
 * 27) Amy stopped someone from attempting to harm/kill Sonic. (Sonic Adventure - Gamma in his storyline; Sonic the Hedgehog - Silver)
 * 28) Eggman's artwork was completely different to the previous of both games, respectively.
 * 29) Both games had Super Sonic planned to be playable in the main levels but was scrapped.

Similarities to Sonic Adventure 2

 * 1) Both games introduced a new hedgehog character. (Sonic Adventure 2 - Shadow; Sonic the Hedgehog - Silver)
 * 2) Throughout the story, Amy met the new hedgehog character and mistook him for being Sonic (Sonic Adventure 2 - Shadow; Sonic the Hedgehog - Silver)
 * 3) Both games have a desert stage (Sonic Adventure 2 - Pyramid Cave; Sonic the Hedgehog - Dusty Desert)
 * 4) In both games Eggman has discovered an immortal/secret being from the past (Sonic Adventure 2 - Shadow; Sonic the Hedgehog - Solaris).
 * 5) Sonic and Shadow were enemies at the first of Sonic Adventure 2, but they became allies at the end of the game like Sonic and Silver in Sonic the Hedgehog.
 * 6) Shadow did not know Sonic after Sonic Adventure 2 because of his falling from the space, but they ended allies again like Silver who did not know Sonic after Sonic the Hedgehog, but they ended allies as well.
 * 7) In both games Shadow used a new Chaos Power (Sonic Adventure 2 - Chaos Control Space Manipulation; Sonic the Hedgehog - Chaos Control Time Space manipulation)
 * 8) Both games introduced a forest Stage (Sonic Adventure 2 - Green Forest; Sonic the Hedgehog - Tropical Jungle.)
 * 9) Both games have introduced a new Super form (Sonic Adventure 2 - Super Shadow; Sonic the Hedgehog - Super Silver)
 * 10) Both introduced a Turtle that can be used for transportation.
 * 11) Both games' final stories have a level which is split into sections each played by most of the supporting and main characters to save the world (Sonic Adventure 2 - Cannon's Core; Sonic the Hedegehog - End of the World (Except for Shadow in Sonic Adventure 2 and Blaze and Sonic in Sonic The Hedghog because the former sacrificed herself in the finale of Silver's story and the latter was killed by Mephiles.)

Videos
US Trailer = Japanese Trailer= Debut Trailer= Playstation 3 Trailer - Environment= European Commercial= German Commercial=

Official

 * , accessed from the Sonic Channel
 * , accessed from the Sonic Channel

Other

 * Sonic the Hedgehog (2006) on Wikipedia
 * at Metacritic
 * at Game Videos
 * at Game Videos

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