Teenage Mutant Ninja Turtles III: Manhattan Cheats (Nes)

On the screen where the title of the game and the choice for number of players appears,
press Up, Up, Down, Down, Left, Right, Left, Right, A, B, Start on Controller 1. Then
select your turtle, and you'll go to the Options screen. If you're playing a two-player
game, press Select before Start.

On the Turtle Select Screen, press Down five times for a one-player game, or press Down 10
times for a two-player game. With this code, whenever you are defeated, the game will
randomly select your next turtle. So, while you may start playing with Leo, after being
defeated, you may continue with Don, Mike, or Raph.