Originally debuting in the spin-off game Knuckles Chaotix, Team Chaotix was re-introduced ... the trio were hired by what was presumably Dr. Eggman to do tasks he assigned to them.

The current reported list of playable characters is: Sonic, Knuckles ... plus Eggman and two more of his creations: Egg Pawn and Metal Sonic. The Chaotix are also here with Vector, Charmy ...