Sonic the Hedgehog 4: Episode III is a 2017 episodic 2D platformer for Playstation 4, Microsoft Windows, Xbox One, Xbox 360, iOS, Android, Ouya and Nintendo Switch as downloadable software. As Episode I was like Sonic 1 and Episode II like Sonic 2, this game is based on Sonic the Hedgehog 3, Sonic & Knuckles, and Sonic Mania.
A world in impact!
After destroying the Death Egg mk.II, Sonic & Tails jump into escape pods and return to Earth safely. After a week, Dr. Eggman goes to his lair, with no idea what to do. Then suddenly, a robotic engine fell on his head. He realises this was of Mecha Sonic, so he went straight to work. After a few hours, he finished his new creation "Mecha Sonic V2." However, little did he know he had a mind of his own. Meanwhile, our heroes fly back their homes, only to see MSV2 shoot at them, therefore crashing down.
Meanwhile, Knuckles was telling all the animals of Angel Island about his adventure and ups and downs with Sonic, when two escape pods crashed onto the floor. They opened up, revealing a blue hedgehog with speedy shoes and an orange fox cub with two tails, both of which looking familiar. Regaining consciousness, Sonic and Tails find Knuckles looking as if to say "Are you okay?"
Our heroes told him about the impact and their past adventures leading to it. Knuckles joined forces with them, and soon, Team Sonic was formed. The heroes travelled to Foreverpeace Island to continue their journey.
- Sonic the Hedgehog: The fastest thing alive thanks to a pair of speedy shoes. Although his attitude is carefree, he always helps the people in need.
- Miles "Tails" Prower: Despite his age, he is brilliant at inventing great things. His two tails enable great flight and great swimming. He can even carry Sonic.
- Knuckles the Echidna: The guardian of the Master Emerald on Angel Island. Now joined forces with Sonic, Knuckles will do anything to have his revenge on Eggman!
- Dr. "Ivo" Robotnik: A literally mad scientist with an IQ of 300, who is planning to use MSV2 for his mean plans. He has a goal: to turn the world into the robotic utopia "Eggmanland."
- Proto Heavy (Eggrobo V2 in Japan): Originally a prototype of a series of robots called "Project Heavy," he is out to cause trouble for this time, not only Knuckles, but Sonic and Tails too.
- Mecha Sonic V2 (MSV2): Made from the scrapped pieces of Silver Sonic, Eggman used him to attack the Sky Sanctuary. Now he has rebuilt him with a different purpose: to destroy his enemies!
Game plays exactly like the classic games, with 4 characters: Sonic and Tails, Sonic, Tails, and Knuckles. Sonic can use his drop dash ability from Sonic Mania, even though it is set before the said game. There is an option to make him have the Homing Attack in the options menu. Tails and Knuckles have the same movesets, though the latter can now punch.
There is a competition mode similar to that of Sonic 2 and 3, and a co-op mode too. And there is a mode called "Follow Who?" in the options menu to have Knuckles and Tails playable, as well as Sonic and Knuckles, Tails and Sonic, Knuckles and Sonic, Tails and Knuckles, and even Sonic and Sonic, Tails and Tails, and Knuckles and Knuckles.
- Foreverpeace Island Zone (Angel Island)
- Act 1: Paradise Beginnings.
- Act 2: Peace In Fire
- Act 3: Enter the Fire Shield
- Boss: Dr. Eggman's Pyro Machine
- Aqua City Zone (Hydrocity)
- Act 1: Sonic Drowns in Water
- Act 2: Now Hiring: Water Shield
- Act 3: It's Dangerous To Get Hosed.
- Boss: Mecha Sonic V2 Is Waterproof!
- Soaring Charger Zone (Flying Battery)
- Act 1: Time For New Heights
- Act 2: Falling Free In The Wind
- Act 3: Electric Shield Powers Up!
- Boss: Tornado V Eggcopter (Tornado Stage)
- Ice Mountain Zone (Icecap)
- Act 1: SSX, Sonic Snowboard Extreme!
- Act 2: It gets warm with the Ice Shield
- Act 3: The Blizzard
- Boss: Proto Heavy Lifts It Up!
- Hidden Palace Zone
- Sonic and Tails Boss: Sonic Wars: The MSV2 Strikes Back!
- Knuckles Boss: Proto Heavy's Phantom Power
- Death Egg mk. II Zone
- Sonic and Tails Act 1: Rumble in Space (Tornado Stage)
- Knuckles Act 1: Hit or Mars
- Act 2: The Team Reunites!
- Boss: Robotic Sonic Resistance
- Intergalactic Battle Zone
- Super Sonic Boss: The Real Doomsday!!! (Super MSV2 and Phantom Proto Heavy)
- Odyssey Zone (Switch DLC/AOC)
- Act 1: A Captivating Life
- Boss: Sonic v. Mechawiggler
Bad Ending (All Characters)
The Death Egg mk. II explodes and crashes into the water once more, while our heroes escape back onto Foreverpeace Island, all in one piece. Sonic and Tails say goodbye to Knuckles as they flew off in the Tornado on the horizon. If you play as Sonic and/or Tails, they fly back and the former or latter jumps off and poses as the logo shows.
If Knuckles, the camera stays on him while Sonic and Tails fly away. He will then lie down and wink as the logo shows.
After the credits, Dr. Eggman can be seen laughing as he juggles the Chaos Emeralds and sits on the Master Emerald, with text below saying "Try Again"
Good Ending (Tails and Knuckles)
Like the Bad Ending, but when the heroes land on Foreverpeace Island, the Chaos Emeralds spill out and Knuckles plants the Master Emerald to its original place.
After the credits, MSV2 and Proto Heavy lay deactivated, then suddenly activate again and stand up, with text saying "We'll Be Waiting For Sonic!"
Great Ending (Super Sonic)
Also like the Bad Ending, but Sonic does not appear, until Tails flies away, when Super Sonic comes in and poses as the logo shows.
After the credits, Dr. Eggman commands 5 Eggrobos to retrieve the lost Phantom Ruby, holding blueprints of Proto Heavy. As they leave, text appears, saying "To Be Continued in Sonic Mania"
Extras and Super Lock-On
Like Episode II, Episode III has the technology of Super Lock-On. If save data from the past episodes are found, or if you complete Episode III with all characters, you can play as Knuckles in each one. And if the same happens after completing the game with Tails, you can play as him in Episode I, all in the Extras menu. It also contains (as DLC/AOC or unlocking manually for no cost)
- Blue Spheres: Episode II: The full game of the special stages in Episode III, with the new Black Sphere, which when you touch it, the consecutive blue spheres and itself turn into rings. Unlocked when you complete all special stages.
- Follow Who?: As mention before, you can play the game with different AI characters. Unlocked when you clear all Act 1 versions in Death Egg mk.II Zone.
- Genesis Mode (Megadrive Mode everywhere else): Changes the graphics and music to the style of S3K. Unlocked when Hidden Palace is cleared, with all characters or not.
- Tornado Go!: The full game of the Tornado stages, with an endless level which challenges the player to getting to the furthest distance. Unlocked when the boss of Soaring Charger Zone is cleared.
- Mecha Madness: A mode that let's you play the game as MSV2, similarly to Episode Metal. Unlocked when game is completed.
- Odyssey Zone: Exclusively to Nintendo Switch, this extra zone is set in New Donk City from Super Mario Odyssey, and the player can use the capture mechanics on enemies. Available as DLC/AOC only.
- Act 2 of Soaring Charger refers to the chorus of "Free" from Sonic Free Riders
- The theme of Intergalactic Battle Zone is actually a Sonic 4 version of Fist Bump, from Sonic Forces.
- Act 3 of Aqua City Zone refers to one of the Legend of Zelda quotes "It is dangerous to go alone"
- The Hidden Palace Sonic and Tails Boss Act is a reference to Star Wars: The Empire Strikes Back.