Sonic the Hedgehog 3, often abbreviated and officially titled in Europe as Sonic 3, is a platform game in the Sonic the Hedgehog series for the Sega Mega Drive/Genesis. It was developed in the United States by members of Sonic Team working at Sega Technical Institute, and was published by Sega, debuting worldwide in the first half of 1994. The game is a sequel to Sonic the Hedgehog 2 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 Eggman from relaunching his ship, the Death Egg.
The game is closely tied to its direct sequel Sonic & Knuckles, as the two games were originally one until time constraints and cartridge costs forced the game to be split into two interlocking parts. Combined, both games have sold over 3.5 million copies. A version re-worked for Xbox 360 was released via Xbox Live Arcade on June 10, 2009 with support for HD televisions.