Will Dr. Robotnik ever take the hint? Not one to fold under pressure, Sonic's evil nemesis has returned with yet another evil plot, and he's enlisted the most vicious machines in the universe to help him. Play as Sonic, Knuckles, Amy, or Tails, trying to collect as many Chaos Emeralds as possible and defeat Robotnik and his mechanical lackeys. The game's regular mode of play is joined by two awesome multiplayer settings: Chaos Emerald Hunt, and Battle.