Sonic the Hedgehog 3 is a 1994 platform video game in the Sonic the Hedgehog series for the Sega Genesis. It was developed by members of Sonic Team working at Sega Technical Institute, and was published by Sega. The game is a direct sequel to Sonic the Hedgehog 2, and follows the end of the game in which Sonic defeated his enemy, Dr. Robotnik. After crash-landing on a floating island, Sonic encounters a new character named Knuckles the Echidna, and must once more retrieve the Chaos Emeralds while also working to stop Dr. Robotnik from relaunching his ship, the Death Egg.
The game is closely tied to its direct sequel Sonic & Knuckles, as the two games were originally developed as a single game until time constraints and cartridge costs forced them to be split into two interlocking parts.
After Sonic defeats Dr. Robotnik at the end of Sonic the Hedgehog 2, his space station, the Death Egg, crash-lands on a mystical floating landmass called Angel Island (or simply ‘the Floating Island’ as it’s called in the game manual). As Dr. Robotnik begins to repair the damaged station, he meets up with Knuckles the Echidna, the last surviving member of an ancient civilization of Echidnas that once inhabited the island. He is also the guardian of the Master Emerald, which grants the island its levitation powers.
Knowing Sonic and Tails will try to track him down, and realizing he can use the Master Emerald to power the ship, Dr. Robotnik dupes Knuckles into believing Sonic is trying to steal his Emerald. Shortly after, Sonic and Tails in their biplane, the Tornado, are in search of Dr. Robotnik. Sonic, possessing the emeralds from the events of Sonic 2, then turns into Super Sonic. As soon as they arrive, Knuckles ambushes Sonic from underground and knocks the Chaos Emeralds from him, returning him to normal. Knuckles steals the Emeralds and disappears inland. As Sonic and Tails travel through the levels, they encounter Knuckles in almost every level, hindering their progress.
In the last level, the Launch Base Zone, the Death Egg launches off for the second time, knocking Knuckles off a pole and sending him plummeting into the water. Sonic travels to a platform on the Death Egg, fights, and defeats Robotnik for the last time. The Death Egg is seen damaged and falling after Robotnik’s defeat, after which it crashes back onto Angel Island- leading into the second half of the story in Sonic & Knuckles.
Sonic 3 improves on the gameplay of previous Sonic titles, in which players collect rings and spin their way through six zones in order to defeat Dr. Robotnik. Like the previous game in the series, Sonic the Hedgehog 2, players can choose to play as either Sonic or Tails, or have Sonic paired with Tails, who can be controlled either by the computer or a second player. Each of the six zones consist of two acts, each with a boss at the end. At the end of every first act boss, players can hit a falling panel to earn points before it hits the ground, where it may sometimes bounce to reveal item monitors. New to the series is the ability to save your progress, with players able to resume their game from the last zone played. If the player clears the game, they can start from any level from their save file.