Teenage Mutant Ninja Turtles: Mutant Melee is a 3D fighting game based on the 2003 animated series. The combat system is similar to earlier games in the series, but with some key differences. It's a competitive vs. fighting game, rather than a traditional one-on-one fighter. Instead, it's an arena-based game for four players, similar to Power Stone.
The game has two main modes: single-player adventure and multiplayer melee mode. In the single-player adventure mode, you play as one of ten characters - including six unlockables - through 100 bouts that test your skills in fighting and dodging enemies or bombs. Completing these sections unlocks additional characters, bonus characters, and stages for melee mode. Melee mode is where the real fun begins, with ten basic and twelve unlockable characters, and nine basic and fifteen unlockable stages to battle it out with.
Melee mode has four game types that mirror popular ones from first-person shooters. You can choose from a knock-out deathmatch mode, where you aim to score the most KOs; Last Man Standing, where you must be the last player standing when others are eliminated; King of the Hill, where you must defend a glowing patch of ground from other players; and Keep Away, where you must hold onto a treasure chest while avoiding opponents trying to beat you up.