Sonic X-treme

Sonic X-treme was a cancelled platform video game in the Sonic the Hedgehog series. Developed by Sega Technical Institute (STI), X-treme was designed to capitalize on the success of Sega's mascot character by being the first fully 3D Sonic game and the first original Sonic title developed for the Sega Saturn. During the course of development, several different styles of gameplay were tried and the plot of the game changed several times.

Originally pitched as a two-dimensional platform game for the Sega Genesis, the game was eventually moved to development on the Saturn and for Windows, intended for release during the holiday season of 1996. However, X-treme became stuck in development hell after several incidents, including an unfavorable visit by Sega of Japan executives and issues with acquiring a game engine, made the deadline difficult to achieve. After two of the lead programmers for the project became ill, the game was eventually cancelled. Reviewers and video game journalists have retrospectively considered the possibility of what Sonic X-treme could have done for the Saturn had it been released, including comparisons to competing mascot video games Super Mario 64 and Crash Bandicoot.