Sonic Unleashed is an action-adventure platform game for the PlayStation 2, featuring Sonic the Hedgehog as he attempts to restore a world ravaged by the villain Dr. Eggman. Following the release of an ancient evil, Sonic transforms into a Werehog at night. The game, developed by Dimps, presents different design elements and gameplay mechanics compared to its counterparts on other platforms.
Sonic the Hedgehog struggles to undo the damage done to the world and himself after Dr. Eggman unleashes an ancient evil which causes him to transform into a vicious Werehog by night.
The version of Sonic Unleashed developed by Dimps for the Wii and PlayStation 2 differs somewhat in design and and mechanics from the one made by Sonic Team for other platforms, including a different engine and fewer high-speed daytime levels.