Are you up 2 it?
Sonic the Hedgehog 2 (ソニック・ザ・ヘッジホッグ２ Sonikku za Hejjihoggu Tsū?) is a platform game developed by Sonic Team in collaboration with Sega Technical Institute, and published by Sega for the Sega Mega Drive/Genesis. It was released in Japan on 21 November 1992 and in North America and Europe on 24 November 1992. It is the sequel to Sonic the Hedgehog and was directly followed by Sonic the Hedgehog 3 in 1994.
The story follows Sonic the Hedgehog and his new sidekick Miles "Tails" Prower on their mission to stop the evil Doctor Robotnik from obtaining the Chaos Emeralds to power his Death Egg. Sonic and Tails must defeat Robotnik's army and free their friends.
Six months after its release, it had sold around six million copies and became the second best selling game on the Mega Drive. The game was compatible with the lock-on feature of Sonic & Knuckles which allowed the player to play as Knuckles in Sonic the Hedgehog 2. It has been included in a number of compilations on a range of platforms. On 11 June 2007, the game was made available on the Wii's Virtual Console, Xbox 360's Xbox Live Arcade on 12 September 2007 and PlayStation 3's PlayStation Network on 19 April 2011.
- 1 Development
- 2 Plot
- 3 Gameplay
- 4 Characters
- 5 Zones
- 6 Reception
- 7 Release
- 8 Cheat codes
- 9 Achievements
- 10 Trivia
- 11 Videos
- 12 References
- 13 External links
While the original Sonic the Hedgehog was designed by Sonic Team in Japan, development duties for Sonic the Hedgehog 2 were handed over to Sega Technical Institute in the United States. However, experienced Japanese Sega members such as Yuji Naka and Hirokazu Yasuhara (the first game's lead programmer and game planner respectively) were brought in to work alongside the American developers.
A prototype of the game was discovered on a Chinese GeoCities site and has been widely distributed on the Internet. (This is widely known as the "Simon Wai prototype".) Only four levels can be played in "normal" gameplay; the rest (including several incomplete stages) have to be accessed through the level select code. Many are not entirely playable, but can be explored using Debug Mode. The prototype is frequently examined by hackers to determine how Sonic the Hedgehog 2 was developed. It was stated in an interview with Yuji Naka that this prototype was from a demonstration cartridge that was stolen at a toy show in New York in 1992. Akinori Nishiyama has also stated that the leak was due to the lack of security at the time.
There was also another prototype version shown on two episodes of Nick Arcade of a beta even earlier than the Simon Wai prototype. Many stages in this beta had music from Sonic the Hedgehog instead of their usual music, such as Emerald Hill Zone playing Star Light Zone's music instead of its usual music, and Chemical Plant Zone plays Marble Zone's music. The beta also features many elements from Sonic the Hedgehog, such as the infamous spike bug (where if Sonic hits one set of spikes and flies into another set, he dies immediately), and even the entirely of Green Hill Zone, albeit highly glitchy and unplayable.
Sonic the Hedgehog was looking for new adventures when he discovered West Side Island. Sonic landed his personal plane, the Tornado, on the island to check it out and relax, not paying attention to the fact that a certain metallic flying object was chasing him and suspiciously landed on the other side of the island.
It is said that a very long time ago, the people of West Side Island used a mysterious stone to advance their civilization and achieve prosperity. However, when those people tried to use the stone for the wrong reasons, their prosperity vanished overnight. It is believed that the kami sealed away the stone within the island's depths.
One day shortly afterward, Sonic noticed a shy orange fox tagging behind him, who nervously scurried back into the welcoming shade of the still palm trees when he was spotted. When Sonic was not looking, the peculiar fox barely managed to keep up with the blue hero. The fox's name was Miles Prower, though he was known as "Tails" due to his two special tails, which often made him the target of bullying. However, something changed in Tails when he saw Sonic come to the island, and he made up his mind that he wanted to be cool like Sonic. Realizing that the young kid was harmless, Sonic made friends with him and allowed him to hang around as he freely explored the island.
On an early afternoon, Tails discovered a lone aircraft stranded at the beach. Being a budding fan of machinery and vehicles, he rushed to take a closer inspection. He was admiring its magnificent build until he noticed that Sonic was taking a nap under its wing. Realizing that Sonic owned the plane, Tails gently retreated to the other side of it so as not to wake him. Suddenly, an ominous flash occurred in the direction of the nearby forest, followed by a terrific explosion. The wild fire blew away various debris, which Tails avoided by taking cover underneath the Tornado as he witnessed robots violently excavating the area. This ceaseless activity threatened to blanket the entire island in its destructive flames.
It turned out that Dr. Robotnik detected the presence of all Chaos Emeralds after following Sonic, including the lost seventh one spoken of in the island's legend. He took the opportunity to kidnap the island's Animals to rebuild his Badnik forces and finish his ultimate weapon, a space station known as the Death Egg. Robotnik now ruled the factories, refineries and cities. He's grabbed control of everything except the seven Chaos Emeralds. The speedy hedgehog went off into the forest to set things right and the curious fox followed.
The heroic duo traveled through West Side Island, rescuing the kidnapped animals and stopping Robotnik's creations every time they face him. After liberating the island from Robotnik's control, the doctor took off to his flying fortress with Sonic and Tails following on his trail on the Tornado. However, the plane gets shot and Sonic has to continue on without Tails. After defeating Robotnik yet again, the doctor retreats to the Death Egg but Tails returns with an upgraded Tornado allowing Sonic to catch up with the doctor. Onboard the space base, the two then have a climactic showdown with Robotnik, who fights from within his deadly Death Egg Robot. In the end, Sonic emerges victorious and the doctor was defeated, causing the Death Egg to explode while Sonic escapes just in time falling through the Earth. He is then saved by Tails where the duo became best friends from the course of the adventure.
The gameplay of Sonic the Hedgehog 2 builds upon the basic set-up of the original Sonic the Hedgehog game. The player finishes each level, generally moving from left to right, within a time limit of ten minutes. Along the way, Rings are collected and Badniks are defeated. Star posts serve as checkpoints; if the player were to lose a life, they would return to the last star post they touched. When the player has collected at least 50 rings, star post will have sparkles on top that the player can jump into for an optional Special Stage.
Although Zones have grown significantly in size since Sonic the Hedgehog, they now consist of two Acts instead of three (with the exception of Metropolis Zone, which has three Acts, and the three final zones, which each have one), and there is a greater emphasis on variety between levels. The gameplay has also become even faster; to that end, Sonic is able to perform a new special move referred to as the Spin Dash Attack. The Spin Dash attack allows Sonic to spin in place, as if revving up an engine, before taking off at high speeds from a stationary start. Sonic's running motion also features longer strides.
Special Stages track Sonic from behind while he runs through a (semi-) three-dimensional half-pipe course filled with rings and bombs. A certain amount of rings must be collected to pass through two checkpoints and then obtain the emerald itself. If the player runs into one of the many bombs (increasing in number as the emeralds are captured) he will lose a set amount of rings, varying depending on the stage. The order of stages is fixed in rising difficulty, and Sonic cannot enter the next stage without passing the previous (unlike Sonic the Hedgehog). Whether the player is able to obtain the emerald or not, Sonic is transported back to the last star post he hit in the zone when the special stage is over and has zero rings.
From the options menu, players can select to either play as Sonic alone, Tails alone or Sonic and Tails. By default, players control Sonic while Tails tags along unhindered. However, a second player may control Tails separately. Should Tails move off-screen, falls off in the void, or dies after getting hit above, he will eventually return. There is minimal difference when playing as Tails instead of Sonic. Tails cannot fly when played as in this game, though he is several pixels smaller than Sonic, meaning he may not have to duck in some instances.
Sonic and Tails' abilities
|Name||Sonic sprite||Tails sprite||Description|
|Push left or right on the D-pad to initiate Sonic's/Tails' movement in either direction. As you hold the button down, Sonic gains speed.|
|Begin walking and hold down the button to make Sonic/Tails gain speed. After a few seconds, he'll break into a run.|
|While running, quickly press and hold the opposite direction on the D-pad to make Sonic/Tails screech to a halt. He'll skid for a short distance, based on how fast he was moving.|
|While standing still, press up on the D-pad to make Sonic/Tails gaze to the sky. Continue holding up for a few moments and the camera pans upward, giving you a view of Sonic's overhead surroundings.|
|While standing still, press down on the D-pad to make Sonic/Tails duck down. As you hold down, the camera pans downward, giving you a view of the stage beneath where Sonic/Tails stands.|
|While moving, press down on the D-pad to make Sonic/Tails curl into a rolling attack. He'll remain in this position until you jump or slow down. The speed of Sonic's/Tails' movement while in spin mode is based on how fast you're moving when you launch it, and also on the terrain Sonic/Tails rolls along.|
|Press , or at any time to make Sonic/Tails leap into the air with a spin attack. The height of the jump is proportional to how long you hold the button down.|
|Green springs in the Oil Ocean Zone can be pushed by running up against them. Continue holding the D-pad against the spring to have Sonic/Tails push it into the wall.|
|Super Spin Dash||While crouching, , or to have Sonic/Tails rev up with a stationary spin. Keep tapping the jump buttons to build up momentum, and let go of the D-pad to dash off with a full speed rolling attack.|
Obtaining all seven Chaos Emeralds by clearing all of the special stages will unlock a new feature; Sonic's ability to change into Super Sonic. Sonic changes into his "Super Form" when he has collected at least 50 rings and jumps into the air. At this point, he glows yellow and is virtually invincible, although he can still die by drowning, getting crushed, falling off the screen, or running out of time. His speed, acceleration and jump height are all increased as well. This means that it is much more difficult to control Sonic in this form, especially when the player needs to make precise jumps. However, his Spin Dash Attack is decreased in effectiveness as the initial velocity is decreased rapidly. Super Sonic consumes one ring per second, and when he has no rings left or he reaches the end of the act, he reverts to his normal state.
If the game is played with Tails only and the player manages to collect all of the Chaos Emeralds, nothing happens.
2 Player VS
In two player versus mode, two players compete against each other -either as Sonic or Tails- in a split-screen race through three regular zones and one Special Stage. Regular zones include Emerald Hill, Casino Night and Mystic Cave and have different music from their one player counterparts, while the Special Stage remains the same as in single player. In the regular levels, players are ranked in five areas (score, time, rings held at the end of the level, total rings collected, and number of item boxes broken), with the player scoring highest in the most levels winning the round, while in the Special Stage, players compete to obtain the most rings. Once one player finishes one of the regular levels, the other player must finish the zone within 60 seconds or lose a life.
In case of a tie, an additional Special Stage round must be completed. Also, to heighten the stakes, there are two unique items in versus-mode: a Teleporter item that instantly switches positions between players in a zone, and a Robotnik item that damages the unlucky player. Furthermore, an optional setting allows that all item boxes in two-player mode are only Teleporters.
- Dr. Robotnik
Robotnik usually appears in his customized Egg Mobile at the end of each Zone's second Act, except in Metropolis Zone (which has three Acts), and Sky Chase Zone, Wing Fortress Zone and the Death Egg Zone (which have only one). Eight hits are required to defeat each boss, excluding the final boss (who takes 12 hits).
- Drill Eggman (Emerald Hill Zone)
- Water Eggman (Chemical Plant Zone)
- Hammer Eggman (Aquatic Ruin Zone)
- Catcher Eggman (Casino Night Zone)
- Submarine Eggman (Hill Top Zone)
- Drill Eggman II (Mystic Cave Zone)
- Submarine Eggman II (Oil Ocean Zone)
- Flying Eggman (Metropolis Zone)
- Barrier Eggman (Wing Fortress Zone)
- Mecha Sonic (Death Egg Zone)
- Death Egg Robot (Final Boss)
- Emerald Hill Zone
- Chemical Plant Zone
- Aquatic Ruin Zone
- Casino Night Zone
- Hill Top Zone
- Mystic Cave Zone
- Oil Ocean Zone
- Metropolis Zone
- Sky Chase Zone
- Wing Fortress Zone
- Death Egg Zone
In Sonic the Hedgehog 2, there are 7 Special Stages. When Sonic has collected at least 50 rings and he hits a Star Post, a red halo of stars will briefly float above it, which Sonic can then jump through to get to a special stage.
Special Stages track Sonic from behind while he runs through a three-dimensional half-pipe course filled with rings and bombs. A set amount of rings must be collected to pass through three checkpoints and eventually obtain the emerald itself. Playing co-operatively with Tails (as seen in the screenshot) raised some of the ring targets in the early stages, for example at the beginning of the first stage 40 rings were required to pass rather than 30. The order of stages is fixed in rising difficulty, and Sonic cannot enter the next stage without passing the previous (unlike Sonic the Hedgehog). Whether the player is able to obtain the emerald or not, Sonic is transported back to the last lamp post he hit in the zone when the special stage is over and has zero rings.
On return from a Special Stage, the entire zone is reset (except the game timer) - the player is without rings but all the collected item boxes and rings reappear (although unfortunately so do the Badniks). Also, if Sonic activates a Star Post, all the Star Posts before that one will be activated as well, whether or not with 50 rings in hand. This created a tactical element to getting the most out of each zone in terms of opportunities to grab Emeralds. It is possible to collect all seven within Emerald Hill Zone, provided the player is careful with the order in which Star Posts are activated (and indeed, very skilled at the Special Stages).
Due to the popularity of its predecessor, Sonic the Hedgehog 2 already had an established fanbase anticipating its release. The game received critical acclaim upon release and was a best seller in the UK charts for 2 months. As of 2006, the game has sold over 6 million copies, making it the second best-selling game for the Sega Genesis/Mega Drive (after the original Sonic the Hedgehog). Out of those 6 million worldwide sales, only 400,000 cartridges were sold in Japan.
|Defunct Games||93% |
|Sonic Retro||93% |
|Computer and Video Games||94%|
|Electronic Gaming Monthly||35/40|
|Game Informer||27.25/30 |
|Official Nintendo Magazine||94% (Wii)|
|Official Xbox Magazine||9/10 (X360)|
|Mean Machines Sega||96%|
|Sega Force Mega||95%|
The game received wide critical acclaim. Based on magazine reviews from the early 1990s, the game has an aggregate score of 93% at both Defunct Games based on 10 reviews and Sonic Retro based on 22 reviews. Based mostly on retrospective online reviews from the 2000s, the game holds an aggregate score of 88.44% at GameRankings based on 8 reviews.
Reviewers praised the game for its large levels, colorful graphics and backgrounds, increased cast of characters, enemies, and music. Upon release, Ed Simrad of Electronic Gaming Monthly stated that the "twice as long" play time offers "more enjoyment for the buck" and that as "a 2 player game, there is twice the fun." He praised the "larger and harder" levels and "quite innovative" new moves, concluding that it is "the best all-around game on the market." GamePro stated that it is "tough to follow up a classic, but Sonic the Hedgehog 2 earns top honors." They stated that "the best thing about Sonic the Hedgehog 2 is that it's just plain fun" and concluded that it gives "plenty of fabulous gaming to pass the time." Andy of Game Informer stated that it is "not as easy as the first and has more variation. The addition of the two-player split screen is great." Jaz of Mean Machines described it as "faster, slicker, more colourful, louder, bigger and much, much tougher than the original," concluding that it is "packed with features, has loads of secrets, and rounds it all up with a superlative two-player mode that'll have your friends queuing round the block to play. Brilliant!"
The game has also been well received in retrospective reviews. GameSpot stated that "time may have eroded Sega's prominence, but it hasn't done much to diminish how sweet Sonic the Hedgehog 2 is," and, along with other reviewers, commented on how it is still a fun game to play. Critics also enjoyed the faster gameplay the game offered in comparison to its predecessor, as well as its new features. Lucas Thomas of IGN praised the new "Spin-Dash" ability, which would prepare Sonic to launch at a faster speed. Thomas also noted that the levels of Sonic the Hedgehog 2 were designed to showcase the character's speed, and was less a "platform-jumping game" than a "platform-running" game, in slight contrast to its predecessor.
The game's main criticisms concern the competitive, split-screen, two-player mode, a new introduction to the series. The game allowed two-player mode in three different zones (Emerald Hill, Casino Night and Mystic Cave). While the mode was generally well-received upon release, several reviewers have criticized the mode's noticeable slowdown, prominent flickering, and squashed play area for each player. However, Lucas Thomas praised the innovation of the new two player mode, quipping that "Mario and Luigi could never run competitively through the same levels, at the same time."  William Burrill of the Toronto Star described the two player racing mode as the "only part of the game that can be faulted," citing that the mode and its split screen view "squeezes the graphics, plumps up the characters and slows down the action."
Electronic Gaming Monthly awarded it as the best Sega Genesis game of 1992, describing it as "the best Genesis cart to come along in a long time!" Game Informer gave Sonic the Hedgehog 2 the Best Action/Adventure Game award, praising it for keeping "the same look and feel of the original Sonic the Hedgehog, while adding a two-player mode, longer levels, new moves, and better animation. Wow!" Electronic Games chose Sonic the Hedgehog 2 as one of the three nominees for their Video Game of the Year award, along with Street Fighter II and NHLPA Hockey '93.
Sonic the Hedgehog 2 has been listed among the best games of all time. In 2000, Game Informer ranked Sonic the Hedgehog 2 number 61 on its "Top 100 Games of All Time" list, calling it "the most challenging and finely polished Sonic the Hedgehog title." They later ranked it the 97th best game of all time in 2009. Mega placed the game at #36 in their "Top Sega Mega Drive Games of All Time" list in 1994. It has also been listed among the best games of all time by Electronic Gaming Monthly (in 1997 and 2001), GameFAQs (in 2004, 2005, 2009 and 2014), GamingBolt, Guinness World Records, NowGamer, Retro Gamer and Yahoo!
The game was released in Japan for the Sega Mega Drive on 20 November 1992. The Sega Genesis release in the United States and the European Mega Drive release came later on 24 November, a Tuesday and the release day was dubbed "Sonic 2's Day". Sega claims that they sold 400,000 copies of Sonic the Hedgehog 2 in the first five days after release. It has since been re-released numerous times.
Sonic the Hedgehog 2 with Sonic & Knuckles
Knuckles the Echidna in Sonic the Hedgehog 2 is a game activated by locking Sonic the Hedgehog 2 to the pass-through cartridge of Sonic & Knuckles that was released later by Sega. The resulting game is almost identical to Sonic the Hedgehog 2, except that the player plays as Knuckles the Echidna. As Knuckles has abilities and weaknesses that Sonic and Tails do not, the game is an overall different experience. Knuckles can glide in the air and climb walls with ease, which allows him to access areas otherwise unreachable by Sonic and Tails, while his weaker jumping abilities make some situations, such as certain boss fights (particularly the final boss of Death Egg Zone), more difficult.
|Sega Mega Drive (Genesis)||Included in Sonic Classics (Sonic Compilation in Europe) on the Sega Mega Drive (Genesis).|
|Arcade||This was one of the games adapted for release in arcades using MegaPlay and MegaTech technology in 1993.|
|Sega Saturn||Playable on the game Sonic Jam for the Sega Saturn console.|
|PC||Included in Sega Smash Pack 2 for the PC.|
|PC||Available in Sega Smash Pack 2 which is included in Sonic Action 4 Pack for the PC.|
|PlayStation 2 / PSP||Sega Genesis Collection for PlayStation 2 and PlayStation Portable also includes this game.|
|GameCube||Available on Sonic Mega Collection for the GameCube.|
|PlayStation 2 / PC / Xbox||Available on Sonic Mega Collection Plus for the PlayStation 2, PC and Xbox.|
|Xbox||Available in Sonic Mega Collection Plus / Super Monkey Ball Deluxe 2 in 1 combo pack for the Xbox|
|GameCube / PlayStation 2||Sonic Gems Collection allows you to play the final boss of this game in the museum mode. If you beat Death Egg Zone under the time limit, you can continue on to the beginning of the game until your time runs out.|
|Play TV Legends||Sega Mega Drive Collection Vol. 2 is a game console which is part of the Play TV Legends plug-and-play series. It has 6 built in games that can be played when the console is connected to the TV. The title game is Sonic the Hedgehog 2. This was released in Europe and Japan in 2005.|
|Play TV Legends||Included in Super Sonic Gold, a console that has 4 built in games, but no cartridge slot. Released in the US and Europe in 2005|
|Mobile Phone||In 2006, this game was ported as a mobile phone game and offered on the Sonic Cafe in Japan and Sega Mobile services elsewhere.|
|Mobile Phone||There are several different versions of the phone game. The game is split into 2 parts, titled Sonic 2 Dash and Sonic 2 Crash. Depending on the screen size, they are either identical to the Genesis original or lacking various elements (including Tails and bosses).|
|Wii||Available for download on the Wii Virtual Console. On 29 October 2015, it was reported that the port would be taken down on 30 October 2015.|
|Xbox 360/PlayStation 3||Available for download on the Xbox 360's Xbox Live Arcade service and later made available for download on the PlayStation 3's Playstation Network service. Released 11 June 2007 for Xbox 360 and 19 April 2011 for PlayStation 3. On 29 October 2015, it was reported that the XBLA port would be taken down on 30 October 2015.|
|PlayStation 3 / Xbox 360||Included in a compilation disk titled Sonic's Ultimate Genesis Collection for the PlayStation 3 and Xbox 360.|
|PC||Sonic PC Collection is a compilation released in New Zealand and Australia in 2009. This compilation includes Sonic Mega Collection Plus which includes Sonic the Hedgehog 2.|
|Nintendo DS||Included on a Game Card titled Sonic Classic Collection for the Nintendo DS.|
|iPhone||Sonic the Hedgehog 2 was ported to iPhone on 20 April 2010. Like the initial port of the original Sonic the Hedgehog, this port removes the capability of inserting cheat codes.|
|Browser||Available for VIP users to play on the PlaySEGA browser game service in 2010.|
The 2013 remaster by Christian Whitehead was available as an update to the earlier iPhone version and also available for Android devices. The revised version adds similar modernized touch-ups as Whitehead's previous works of Sonic the Hedgehog CD and Sonic the Hedgehog, adding exclusive features such as Knuckles as a playable character, a fully playable Hidden Palace Zone and a boss attack mode.
Announced on April 2015 as part of Sega 3D Classics' third set, 3D Sonic the Hedgehog 2 was released on July 22, 2015 in Japanese Nintendo 3DS eShop. After two other titles in the third set, 3D Sonic the Hedgehog 2 was released on October 8 in North America priced at $5.99. Like the previous 3D Sonic the Hedgehog, the port is part of series of the Mega Drive games re-released with the feature to play in 3D. The port features the option to use save states, change the display and audio settings, along with the new mode titled "Ring Keeper" that allows the player to start each Zone with 10 Rings and only lose half of them during the mode. Beating the game once unlocks "Super Sonic Mode" in which the player starts with 50 Rings and All Chaos Emeralds. The multiplayer mode of this port is utilized with co-op play.
- Display Tails' name as Miles: At the title screen press the following in order: Up, Up, Up, Down, Down, Down, Up. This can be done again to revert Miles' name back to Tails. In the Japanese release Miles is the default name and entering the code will change his name to Tails.
- Act select: - At the Options Sound Test, play the following tunes in order: 19, 65, 09, and 17, which makes the Ring sound play, then press Start to return to the intro/title screen. Once there press Start while holding to enter the Act select. During any Act, by pausing the game, press A to return to the Act Select.
- 14 Continues: At the Options Sound Test, play the following tunes in order: 01, 01, 02 and 04, then the select Player Select to start the game with 14 continues. Oddly enough entering this code will cause all sound test options to be overwritten with the music for Oil Ocean Zone.
- Debug Mode: At the Act Select Sound Test, play the following tunes in order: 01, 09, 09, 02, 01, 01, 02, and 04, activating a Ring chime, and unlock Debug Mode. Then highlight any Act and press Start while holding .
- All 7 Chaos Emeralds: At the Act select Sound Test, play the following tunes in order: 04, 01, 02, and 06, which plays Chaos Emerald music, and get all seven Chaos Emeralds.
- The English manual, which was released shortly after the Japanese version, simplified the storyline. It implied that the game instead took place on the same island as the previous adventure, and also altered Tails' character so that he had looked up to Sonic ever since he was a cub, showing off imitations of his role model's famous moves in front of the forest animals. Beginning with Sonic Adventure, the original Japanese storyline was adopted worldwide, and the localized storyline was virtually discarded.
- This is the only 2D Sonic game where the player doesn't get a "Try Again" message after completing the game without collecting all Chaos Emeralds.
- In the second trailer for Sonic the Hedgehog 4: Episode I, during the Sonic the Hedgehog 2 section, Sonic's running animation from the Nick Arcade and Simon Wai prototypes is seen instead of the final version.
- The Debug Mode and 14 continues codes correspond to the English release date of this game (01, 09 ,09 ,02 ,01 ,01 ,02, 04 which is 24 November 1992), although the latter doesn't need the year.
- On the cover for the game in versions outside Asia, Robotnik's usual blue glasses appears to be depicted as empty black eyes. This could be the reason why the older Sonic television shows and comics portrayed Robotnik with black and red eyes.
- This is the first Sonic game to feature 2 Player mode.
- This is the first Sonic game to use the Spin Dash.
- This was the first main series game to have all seven Chaos Emeralds.
- This game was the Genesis' bestseller due to the success of its prequel and the fact that the game was packaged with the Sega Genesis.
- In this game, there is a Super Sonic code that allows the player to obtain all Chaos Emeralds when inserting the level select code. This lets the player turn into Super Sonic with at least 50 rings without completing any Special Stages.
- This game is represented in Sonic Generations. Chemical Plant reappears as the second level of the Classic Era in the home version, while Casino Night appears as the second stage in the portable version. A remix of the 2-player results music can be heard while purchasing Skills in the Skill Shop. One of Sonic's wait animations, in which he looks at his wrist and lays on the ground, also returns as one of Classic Sonic's wait animations. Finally, the Death Egg Robot appears as the Gate Boss of the Classic Era in the home version. During the boss fight, a remix of the Death Egg Robot's theme can be heard.
- The app icon for the initial iPhone version of Sonic the Hedgehog 2 uses recycled artwork from Sonic Advance 2.
- Players are awarded with a "Perfect Bonus" of 50,000 if they complete an Act after collecting every ring in the Act and losing none. This is extremely difficult from Chemical Plant Act 2 and onwards, as Acts will have more paths, some of which become unreachable after a certain spot.
- The ending theme of Sonic the Hedgehog (2006), "Sweet Dreams," sounds very similar to the ending theme of this game.
- The music that also plays on the options menu is very similar to the ending theme of Sonic the Hedgehog 2.
- On the back of the American Sonic the Hedgehog 2 box, the screenshot of Sonic and Tails in the Oil Ocean Zone is actually a pre-release version of this Zone. A switch can be seen on the right side of the screenshot. When pressed, it would release a large ball from the floor and roll right into the ocean (as seen in the Simon Wai prototype). The switch and the ball did not appear in the final version of this Zone but can still be accessed in the Debug Mode in the final version. The screenshot of Aquatic Ruin Zone is also from a prototype version.
- In the U.S. instruction manual of Sonic the Hedgehog 2, page 7 has a screenshot of the title screen from the Beta 4 prototype. On page 9, the screenshot of the Oil Ocean Zone is also in from a prototype. Its background is different from the final version (most notably, the silver silo in the background is on the right side in the screenshot, but it is located on the left side in the final version).
- Interestingly, the sprite of Super Sonic used for the Super and Extended Super achievements is in fact a fan-made Sonic Battle sprite from a sprite sheet made by JoeTE.
- Boss Attack Zone in the 2013 mobile re-release was originally conceived as a complete one-act level called Egg Gauntlet Zone, which would have used new assets (as well as those from Sonic Crackers) to form platforming sections between each boss. Sonic Team did not agree with changing the location, colors or graphic style of the bosses, so Christian Whitehead deleted the Zone in favor of the more direct boss endurance mode.
- Dr. Eggman has a beard in the US/EU box art, even though he doesn't have one in the game.
- Yuji Naka mentioned in an interview that he took the code from the original Sonic the Hedgehog and optimized it before Sonic the Hedgehog 2 started production.
- Virtual Console Mondays: June 11, 2007. http://www.nintendoworldreport.com. Retrieved on 2007-10-21.
- Sonic the Hedgehog 2 on Xbox LIVE Arcade. http://www.xbox.com. Retrieved on 2007-10-21.
- Sonic Team. http://uk.games.ign.com. Retrieved on 21 October 2007.
- GameSpy: Sega's Yuji Naka Talks!. GameSpy. Retrieved on 27 February 2007.
- Kikizo Games: Features: Sonic Team Interview November 2005 (Page 2). Kikizo Ltd. Retrieved on 27 February 2007.
- Sonic Team (1992). Sonic the Hedgehog 2 Instruction Booklet. Sega.
- Lucas M., Thomas (2007). IGN's Sonic the Hedgehog 2 Review. IGN. Ziff Davis. Retrieved on 2007-10-21.
- "Official Gallup UK Mega Drive Sales Chart". Mega (6). March 1993.
- Boutros, Daniel (2006-08-04). A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games. Gamasutra. Retrieved on 2006-12-08.
- Sonic the Hedgehog 2. GameRankings. Retrieved on 2012-02-03.
- Sonic the Hedgehog 2: What Did the Critics Say in 1993?, Defunct Games
- Sonic the Hedgehog 2, Computer and Video Games, issue 132
- Electronic Gaming Monthly, 1998 Video Game Buyer's Guide, page 87
- ソニック・ザ・ヘッジホッグ2. Retrieved on 2014-12-29.
- GameFan, volume 1, issue 2, December 1992, pages 9 & 14-17
- Game Informer, issue 8 (January/February 1993), pages 56-57
- "Classic Reviews: Sonic the Hedgehog 2". Game Informer 12 (109): 104. May 2002.
- Provo, Frank (2007). Sonic the Hedgehog 2 Review. GameSpot. Retrieved on 2007-10-21.
- East, Tom (2008-01-11). Sonic The Hedgehog 2: The blue hedgehog returns. Official Nintendo Magazine. Archived from the original on 2013-10-31. Retrieved on 2012-02-03.
- Bad Influence!, issue 2, pp. 46-47, 1993
- Electronic Games, volume 1, issue 3, December 1992, pp. 72-74
- "Review: Sonic the Hedgehog 2". Mean Machines Sega (2): 60–3. November 1992. Archived from the original. Template:Citation error. http://info.sonicretro.org/Review_-_Sonic_the_Hedgehog_2_%28Mean_Machines_Sega,_November_1992%29. Retrieved on 2012-02-03.
- "Game Review: Sonic the Hedgehog 2". Mega (Future Publishing) (2): 36–41. November 1992. Archived from the original. Template:Citation error. http://www.outofprintarchive.com/catalogue/mega/MEGA2.html. Retrieved on 2012-02-03.
- Sonic 2, MegaTech, issue 11, pp. 3-15
- "Sonic the Hedgehog 2". Mega Zone (25): 31–33. January 1993. Archived from the original. Template:Citation error. http://info.sonicretro.org/Review_-_Sonic_the_Hedgehog_2_%28Megazone,_January_1993%29.
- "Reviewed: Sonic the Hedgehog 2 (Mega Drive)". Sega Force (Impact Magazines) (12): 14–6. December 1992. Archived from the original. Template:Citation error. http://www.smspower.org/Scans/SegaForce-Magazine-Issue12?gallerypage=16. Retrieved on 2012-02-03.
- "Sonic 2". Sega Force Mega (Impact Magazines) 2 (1): 91. August 1993.
- Sonic the Hedgehog 2, Sega Pro, issue 15 (Christmas 1992), pp. 52-59
- Svenska Hemdatornytt, volume 1993, issue 1, p. 37 (January 1993)
- "Electronic Gaming Awards". Electronic Games (38): 26–7. January 1993. Archived from the original. Template:Citation error. http://archives.tg-16.com/00_happy_new_year_1993.htm. Retrieved on 5 February 2012.
- "Buyer's Guide: Best Game of the Year (Genesis)". Electronic Gaming Monthly. 1993. "Sega's famous mascot -- Sonic the Hedgehog is back for his second visit to the Genesis, and this version is hot! With 8 megabits of memory good ol' Sonic has a lot more room to do cool tricks and this is what makes this version stand head and shoulders above all the other Genesis games that came out this year. All in all, Sonic 2 is the best Genesis cart to come along in a long time!"
- Game Informer, issue 8 (January/February 1993), page 34
- "Game Zero's Sonic the Hedgehog 2 Review". Game Zero. 1993. Archived from the original. Template:Citation error. http://www.gamezero.com/team-0/final_word/genesis/sonic_hedgehog_2.html.
- Sonic the Hedgehog VC Review. IGN (2007-01-26). Retrieved on 2014-11-18.
- Sonic the Hedgehog 2 Gets the Remastering Treatment, With the Long-Lost Hidden Palace Level Restored. 148Apps. Steel Media Ventures. Retrieved on 2014-11-18.
- Sonic the Hedgehog 2 Review. IGN (2007-06-11). Retrieved on 2014-11-18.
- Burrill, William (1992-12-12). "This Sonic is super, too". Toronto Star: F4.
- "Top 100 Games of All Time". Game Informer 11 (100): 28. August 2001.
- Game Informer's Top 200 Games of All Time, Game Informer, 2009
- Mega (Future Publishing) (26): 74. November 1994.
- EGM Top 100. Electronic Gaming Monthly (November 1997). Retrieved on 2011-06-01.
- Top 100 Games of All Time, Electronic Gaming Monthly, 2001
- Spring 2004: Best. Game. Ever.. GameFAQs. Retrieved on July 16, 2008.
- Fall 2005: 10-Year Anniversary Contest—The 10 Best Games Ever. GameFAQs. Retrieved on July 16, 2008.
- Spring 2009: Best. Game. Ever.. GameFAQs. Retrieved on June 10, 2009.
- Top 100, GameFAQs, 2014
- Top 100 greatest video games ever made, GamingBolt, GameRevolution, 2013
- Guinness World Records 2009 Gamer's Edition reveals the Top 50 console games of all time, Guinness World Records Gamer's Edition, 2009
- 100 Greatest Retro Games, NowGamer, Imagine Publishing, 2010: part 1, part 2, part 3, part 4
- Retro Gamer, issue 1, p. 30, January 2004
- The 100 greatest computer games of all time, Yahoo!, 2006
- GamesRadar (17 November 2016). Xbox One plays these Xbox 360 games with backwards compatibility. Retrieved on 24 December 2016.
- 3rd set of Sega 3D Classics coming to Nintendo 3DS, including Sonic 2! (14 April 2015). Retrieved on 18 September 2015.
- 3D Sonic the Hedgehog 2 releases on July 22nd in Japan for the 3DS eShop (15 July 2015). Retrieved on 18 September 2015.
- 3D Sonic The Hedgehog 2 Joins Sega’s Other 3D Classics On October 8. Siliconera (28 September 2015). Retrieved on 29 September 2015.
- 3D Sonic the Hedgehog 2 Trailer & Details Released (16 July 2015). Retrieved on 18 September 2015.
- Sonic Retro Thread Page in which Christian Whitehead explains Egg Gauntlet Zone.
- Sonic the Hedgehog 2 at Wikipedia, the free encyclopedia.