Sonic 4 Episode III is the third episode of Sonic the Hedgehog 4 and also the final one. It was first released in 2013, for Xbox 360, PlayStation 3, Xbox One, iOS, Android and PC, with a special lock-on extra, Sonic 4 Episode Silver. It was re-released in Sonic 4 - The Complete Trilogy, for Nintendo Switch, PlayStation 4, Xbox One, iOS, Android and PC.
Sometimes, after Sonic defeated Egg Heart with his buddy Miles "Tails" Prower, the entirety of Death Egg Mk. II has been fully destroyed, with the exception of the Master Emerald.
We then cut to Sonic using his propeller shoes. He sees a huge, ruined and completely deserted island. When he reads the sign, the island is known as the Ascquire Island. Knuckles the Echidna, who has a long vacation, searchs where is the island's tropical landscape. Knuckles and Sonic notice that the Master Emerald fell from the sky, from its altar. Knuckles then reveals that Doctor Eggman also taken the Chaos Emeralds, and shattered them into the all-new Special Stages! Sonic covers his face, and sees a giant, sparkly silver armored airship, with a black Eggman's face printed on the side.
Just after the armored airship disappeared, Mecha Sonic took the Master Emerald and placed it in the Skyhigh Skybase Zone. Sonic sets off and starts his adventure through 6 zones and 7 Special Stages. The new addition is that Sonic can hit the Switch Monitor and switch into Knuckles and vice versa.
Sonic the Hedgehog: Sonic is a bright blue-hued hedgehog. He lands on the Ascquire Island along with Knuckles and the Master Emerald. He must speed off on an another adventure through the Ascquire Island along with Knuckles, through 6 zones and 7 Special Stages!
Knuckles the Echidna: After Sonic & Knuckles, he keeps the Master Emerald in the Sky Sanctuary. However, it survived the huge destroy of the Death Egg Mk. II, and taken by Mecha Sonic to the Skyhigh Skybase Zone. Knuckles must team up with Sonic and adventure through the Ascquire Island to get the Master Emerald and the seven Chaos Emeralds.
Mighty the Armadillo: The long-lost member of Team Chaotix, Mighty the Armadillo is a strong but very fast armadillo rescued after the mini-boss battle against Fang the Sniper, in Neon City Zone. He, like Sonic, can Spin Dash, Homing Attack and Super Peel Out, but he can also do a Hammer Drop. When Mighty becomes Super Mighty, his Hammer Drop becomes a Comet Dive, which can kill all Badniks in the area.
Doctor Eggman: Sonic's biggest rival is back, with his all-new invention - the E.G.G. Headquarters!!! He is more destructive, with his all-new machines!
Mecha Sonic: After Sonic & Knuckles, Mecha Sonic reappears, and is not fooling anymore! Get ready for a huge rumble, as the mini-boss of both Black Mansion Zone and Skyhigh Skybase Zone.
Silver Sonic v2.0: One of Doctor Eggman's robots. He is a sparkly silver robot with red shoes and white accents. The main hero of Episode Silver.
Ascquire Hill Zone - The tropical landscape of Ascquire Island. It introduces the Sky Mobile in its Act 3, also the mini-boss act.
Neon City Zone - A colored city and also the casino, where badniks roam the brightened jackpots.
Black Mansion Zone - A dark landmark with a creepy castle, where Eggman keeps his second HQ.
Coldopolis Zone - A very cold city with many icebergs and frozen statues all over the city. Introduces the Marine Mobile.
Skyhigh Skybase Zone - A gigantic skybase that begins in an act where you pilot the Sky Mobile.
E.G.G. Headquarters Zone - Eggman's huge headquarters, where he builds all badniks and keeps his previous robots as scrap metal.
Atomic Space Zone - The cosmos above Mobius, where you fight the joined forces of Mecha Sonic and Eggman. Requires all Chaos Emeralds.
Ascquire Hill Edit
Mini-boss: DD Wrecker
Boss: Egg Zapper
Neon City Edit
Mini-boss: Fang the Sniper
Boss: Egg Bobber
Black Mansion Edit
Mini-boss: Mecha Sonic (1st phase: in the Energy Ship, 2nd phase: on foot)
Boss: Haunted Egg
Mini-boss: Ice Hands
Boss: Double Iceball
Skyhigh Skybase Edit
Mini-boss: Magnet Mecha Sonic
Boss: Tesla Egg
E.G.G. Headquarters Edit
Mini-boss: Egg Pistons mk.II
Bosses: Egg Phoenix, Egg Bomber Tank