Sonic the Hedgehog 3

 Sonic the Hedgehog 3 is a 1994 platform game developed and published by Sega. It is part of the Sonic the Hedgehog series and follows Sonic the Hedgehog 2 (1992). After Doctor Robotnik's spaceship, the Death Egg, crash-lands on a mysterious floating island, Sonic and Tails attempt to retrieve the Chaos Emeralds to stop it from relaunching. Sonic 3 introduces Knuckles the Echidna, the island guardian, who lays traps for Sonic and Tails. Gameplay is like previous entries, with players traversing side-scrolling levels at high speeds while collecting rings and defeating enemies.

Development began in January 1993, shortly after the release of Sonic 2. It was initially developed as an isometric game like Sonic 3D Blast (1996) but became a conventional 2D platformer due to time constraints. Sonic 3's production took place simultaneously with Sonic & Knuckles; they were developed as a single game until time constraints and cartridge costs forced the developers to split it. The Sonic 3 cartridge can be attached to an adapter on the Sonic & Knuckles cartridge, creating a combined game, Sonic 3 & Knuckles. Pop musician Michael Jackson reportedly composed portions of the soundtrack but left the project and went uncredited.

Sonic 3 was released for the Sega Genesis in North America and Europe in February 1994, and in Japan in May. As with its predecessors, it was a critical and commercial success, with critics seeing it as an improvement over previous installment. It sold over one million copies in the United States, making it one of the bestselling Genesis games. Alongside Sonic & Knuckles, a Windows port was released through the Sonic & Knuckles Collection (1997). The game has also been rereleased via emulation and compilations for various platforms, such as Sonic Mega Collection (2002) and Sonic's Ultimate Genesis Collection (2009).