Sonic the Hedgehog 3 is a platform game developed by Sega for the Sega Genesis. It serves as a direct sequel to Sonic the Hedgehog 2, continuing the story where Sonic lands on a floating island. Players control Sonic and his new ally Knuckles the Echidna as they work to collect the Chaos Emeralds and thwart Dr. Robotnik's plans to resurrect the Death Egg.
The game is a sequel to the Sonic the Hedgehog 2 for the same system and follows on directly from the end of the game, in which Sonic defeated his enemy, Dr. Robotnik; crash-landing on a floating island, Sonic encounters new character 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.