It's thought that the four characters playable in the multi player and story mode games are based on four of the main Sonic the Hedgehog characters - Billy is Sonic, Chick Poacher is Tails, Bantam Scrambled is Knuckles and Rolly Roll is Amy. The Hatcher characters use similar colors and copy poses as well. For example, on the game's box art, Billy is in the same pose as Sonic from official Sonic Adventure 2 artwork.