Teenage Mutant Ninja Turtles 3 Game System: Nintendo System Cheat Category: Cheat Game Company: Unknown Game Category: Unknown Hint, Cheat, Walkthrough:   Teenage Mutant Ninja Turtles 3: The Manhattan Project ===================================================== =>Stage Select, Lives, Sound Test: Enter this code on the title screen BEFORE the demo appears - U U D D L R L R A B START =>Auto Mode: On the Turtle Selection Screen, press Dx5 (for a 1-player game) or Dx10 (for a 2-player game). When you play, after one Turtle is defeated the next Turtle will be chosen randomly, rather than from the normal order.