Sonic the Hedgehog 4 is an episodic 2D side-scrolling game series for iOS, PC, PlayStation 3, Xbox 360, Android and more. It takes place firmly after Sonic the Hedgehog 3 & Knuckles, although the saga is more of a continuation of the previous side-scrolling Sonic games, with each Episode resembling one or more of the previous installments, as almost all of the enemies and bosses seen in each episode were seen before in one of those games.
- Sonic the Hedgehog 4: Episode I
- Sonic the Hedgehog 4: Episode II
- Sonic the Hedgehog 4: Episode Metal (Lock-on extra)
Sometime after the events of Sonic the Hedgehog 3 & Knuckles. With the Death Egg destroyed and Angel Island floating again, Sonic parts with Tails and Knuckles and heads off to explore new territories on his own. However, Sonic's break is cut short when a vengeful Dr. Eggman, who had survived their last encounter, has returned and has taken measures to get rid of Sonic with a new and improved army of Badniks. Despite Dr. Eggman's best efforts, Sonic destroys each of his refined creations and chases the madman to his newest lair, the E.G.G. Station Zone. There, Sonic defeats each of his creations once again, including the powered-up Death Egg Robot from Sonic's first encounter on the Death Egg. After destroying the mech and the space station, Sonic returns safely back on his planet and celebrates his victory in Splash Hill Zone with his Animal friends.
A short while after the events of Episode I, Little Planet (where the events of Sonic the Hedgehog CD took place) reappeared once more. Dr. Eggman, after being defeated in the previous installment, sends a monitor to Stardust Speedway to revive the destroyed Metal Sonic. Metal Sonic then flies to Mad Gear Zone zone where Eggman uses the base's machines to restore Metal to working order. Eggman then sends Metal out to Lost Labyrinth Zone to retrieve a mysterious object to empower Metal Sonic even further. After traveling through Casino Street Zone and Splash Hill Zone, Metal Sonic sees Sonic and Tails in the Tornado flying off in the distance. Using a nearby rocket, Metal Sonic sets off in pursuit.
Meanwhile, Sonic discovers that the mad doctor is back, and recruits his buddy Tails to help him face this new threat and save the Planet once more from destruction. Sonic and Tails pursue Eggman and Metal Sonic through several areas and confront him at his Sky Fortress. After being defeated by Sonic and Tails, Eggman and Metal retreat to the Death Egg mk.II, Eggman's newly created space station built around Little Planet. Sonic and Tails have a final confrontation with Metal Sonic (in a race that mimics their confrontation at Stardust Speedway) and defeat Metal Sonic once again. Afterwards, the two of them face Eggman's latest creation: the Egg Heart. Sonic and Tails defeat this machine and escape the de-activating Death Egg, saving the planet once again, but leaving the fate of Little Planet an uncertainty.
Characters in the series
- Egg Mobile Hammer Ball (Splash Hill Zone)
- Catcher Eggman (Casino Street Zone)
- Eggmobile (retreat) (Lost Labyrinth Zone)
- Flying Eggman (Mad Gear Zone)
- Boss Rush (E.G.G. Station Zone)
- Death Egg Robot (E.G.G. Station Zone)
- Egg Serpentleaf (Sylvania Castle Zone)
- Metal Sonic (White Park Zone)
- Egg Scrap Mech (Oil Desert Zone)
- Metal Carrier (Sky Fortress Zone)
- Metal Sonic and Eggmobile (Death Egg MK.II Zone)
- Metal Sonic (Death Egg MK.II Zone)
- Egg Heart (Death Egg MK.II Zone)
- Splash Hill Zone (Episode I/Metal)
- Casino Street Zone (Episode I/Metal)
- Lost Labyrinth Zone (Episode I/Metal)
- Mad Gear Zone (Episode I/Metal)
- E.G.G. Station Zone (Episode I)
- Stardust Speedway (cutscene)
- Sylvania Castle Zone (Episode II)
- White Park Zone (Episode II)
- Oil Desert Zone (Episode II)
- Sky Fortress Zone (Episode II)
- Death Egg Mk.II Zone (Episode II)
- Super Ring: Holds ten rings
- 1-Up: Extra Life
- Power Sneakers: Makes you run faster for a limited time
- Invincibility: Makes you invincible for a limited time
- Shield: Protects you from a single hit
- Special Combination: Attacks all badniks and gains points and rings (Episode II only)
Special Stages in Sonic the Hedgehog 4: Episode I play akin to ones in the first game, where Sonic must navigate a maze to reach the Chaos Emerald, collecting rings and avoiding the exit blocks. This time, the rotation is controlled by the player instead of automatically. Controllers with motion control support can use either a traditional control method or by tilting the controller to control the rotation.
Two significant differences between these stages and the original ones are the inclusion of ring gates and a time limit. Ring gates are barriers that prevent the player from crossing into the next area of the stage, but can be passed once the appropriate number of rings, shown on the gate, have been collected. A time limit also kicks in at the start of each stage and boots the player out if they haven't collected the Emerald in the time frame. The starting amount varies by level, but can be extended in five, ten or fifteen second increments by collecting orbs around the stage.
Once a Special Stage has been completed, it can be replayed on the level select stage in either Score or Time Attack modes, with a 1-Up replacing the Emerald.
Special Stages in Sonic the Hedgehog 4: Episode II play akin to the Sonic the Hedgehog 2 Special Stages. Like in Sonic the Hedgehog 2, Sonic and Tails must collect a certain amount of rings, the amount increasing after hitting a checkpoint, however, unlike Sonic the Hedgehog 2, Tails can collect rings, but will not lose his share if he touches any bombs, although this is only true for Single Player. Also, unlike Sonic the Hedgehog 2, the player can boost by holding the Tag Action button, and while there is no time limit, but there is a timer, used for Time Attack scores.
- The prototype of Knuckles' Chaotix known as Sonic Crackers was also called Sonic the Hedgehog 4 in some magazine articles.
- While the Wii saw a prominent release for Episode I, Episode II was not released for it as the WiiWare service has a 40 MB size limit.
- Additionally, the difference in sound quality between the WiiWare version of Episode I and the other versions is that the former has been compressed to fit the size limit.
- In Sonic Generations, Splash Hill Zone's music track is unlockable to listen to in the game.
- During the development of Sonic the Hedgehog 4: Episode I, it was the idea to make Sonic the Hedgehog 4 a trilogy, but it was scrapped. However, it has been hinted that it is possible that a potential Sonic the Hedgehog 4: Episode III video game can be released.
- This is the only Sonic game to receive a copying lock within its files on the PlayStation 3 version. The lock disallows the game to be copied to a USB stick or anything that grants it access to a PC. This is one of the four known PlayStation 3 games to have this.