Sonic the Hedgehog 4

Sonic the Hedgehog 4 is a 3D side-scrolling game for the PS3, Xbox 360, Nintendo Wii, IOS, Android and the PC. It takes place after Sonic 3 & Knuckles, although the saga is more of a continuation of Sonic CD. The game started in 2010 with Episode I, while Episode II and Episode Metal have been recently released.

The saga is being designed as a throwback to the previous side-scrolling Sonic games, with each Episode resembling one of the previous installments.

Games

 * Sonic the Hedgehog 4: Episode I
 * Sonic the Hedgehog 4: Episode II
 * Sonic the Hedgehog 4: Episode Metal (Lock-on extra)

Episode I
The story is set sometime after Sonic 3 & Knuckles. With the Death Egg destroyed and Angel Island floating again, Sonic the Hedgehog parts with Miles "Tails" Prower and Knuckles the Echidna and heads off to explore new territories on his own. However, Doctor Eggman has survived his latest defeat, and has taken measures to defeat Sonic by enhancing his past creations and mechs. 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 Giant Mech 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.

Episode Metal
Some time after the events of Episode I, the Little Planet, where Sonic CD took place, reappeared once more. Doctor Eggman, 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 bases machines to restore Metal to working order. Eggman then sends Metal out to Lost Labyrinth Zone to retrive a mysterious object to power 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.

Episode II
Meanwhile Sonic discovers that the Doctor and Metal Sonic are 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 Zone after defeating the evil duo there, Eggman and Metal retreat to the Death Egg Mark II, Eggman's newly created space station built around the Little Planet. Sonic and Tails have a final confrontation with Metal Sonic, in a race that mimics their confrontation at Stardust Speedway and defeats Metal Sonic once again. Afterwards Sonic and Tails 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 the leaving the fate of Little Planet an uncertainty.

Playable

 * Sonic the Hedgehog
 * Miles "Tails" Prower
 * Metal Sonic

Non Playable

 * Dr. Eggman

Badniks

 * Bubbles
 * Buzzer
 * Chopper
 * Motobug
 * Newtron
 * Batbot
 * Burrobot
 * Jaws
 * Orbinaut
 * Shellcracker
 * Slicer
 * Spiker
 * Crawl
 * Asteron
 * Spikes
 * Fullboar
 * Steelion
 * Scarabesque
 * Sandworm
 * Chop Chop
 * Snowy
 * Zoomer
 * Mantis
 * Balkiry
 * Turtloid
 * Clucker

Splash Hill Zone

 * Wrecking ball Eggmobile

Casino Street Zone

 * Catcher Eggman

Lost Labyrinth Zone

 * Trap Eggmobile

Mad Gear Zone

 * Flying Eggman

E.G.G. Station Zone

 * Boss Rush
 * Wrecking ball Eggmobile
 * Catcher Eggman
 * Trap Eggmobile
 * Flying Eggman
 * Death Egg Robot

Sylvania Castle Zone

 * Egg Serpentleaf

White Park Zone

 * Metal Sonic

Oil Desert Zone

 * Egg Scrap Mech

Sky Fortress Zone

 * Metal Carrier

Death Egg mk.II Zone

 * Metal Sonic and Eggmobile
 * Metal Sonic
 * Egg Heart

Zones

 * 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
 * Stardust Speedway (cutscene)
 * Sylvania Castle Zone
 * White Park Zone
 * Oil Desert Zone
 * Sky Fortress Zone
 * Death Egg Mk.II Zone

Key Items

 * Chaos Emeralds
 * Rings
 * Item boxes
 * Time Stone

Item Boxes

 * Main article: Item box
 * Super Rings (Holds ten rings)
 * 1-UP (Extra Life)
 * Power Sneakers (Makes you run faster for a limited time)
 * Invulnerability (Makes you invincible for a limited time)
 * Shield (Protects you from a Single hit)
 * Golden Monitor (Attacks all badniks and gains points or rings)

Episode I
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.

Episode II
Special Stages in Sonic the Hedgehog 4: Episode II play akin to the Sonic 2 Special Stages. Like in Sonic 2 Sonic and Tails must collect a certain amount of rings, the amount increasing after hitting a checkpoint, however, unlike Sonic 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 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.

Trivia

 * Episode Metal and Episode II are on every console and IOS system, except for the Nintendo Wii, as the system's online service, WiiWare, 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 made as a song track in the games, by unlocking it in the game.