The game follows Tails, Knuckles, Dr. Eggman and Metal Sonic as they are terrorized by a bloodthirsty monster who's out to kill them for unspecified reasons. However, these motives, and the paths these four take, will define their future and have an impact on their lives forever.

The game follows Tails, Knuckles, Dr. Eggman and Metal Sonic as they are terrorized by a bloodthirsty monster who's out to kill them for unspecified reasons. However, these motives, and the paths these four take, will define their future and have an impact on their lives forever.