Perfect Chaos' appearance in this game is different to its appearance in Sonic Adventure; in Sonic Adventure, it was a creature made entirely out of water, whereas in Sonic Generations, it has scaly, reptile-like skin. According to an interview with Takashi Iizuka in the Prima Strategy Guide for Sonic Generations, Perfect Chaos' 2011 design is how the team had originally planned the monster; it had had to be changed in Sonic Adventure due to the technical restraints of the Dreamcast.