Teenage Mutant Ninja Turtles 3: Manhattan Project

Cheat mode:
Press Up(2), Down(2), Left, Right, Left, Right, A, B, Start at the title screen before the demonstration starts.
Note: For two player mode press Up(2), Down(2), Left, Right, Left, Right, A, B, Select, Start.
Level select, extra lives, and sound test options will now be available.

Auto turtle selection:
Press Down(5) at the character selection screen, or Down(10) at the same screen for two player mode.
After a turtle is defeated, the next turtle will automatically be selected randomly.
Alternately, rapidly tap Left, Right repeatedly at the character selection screen.

Save energy:
Repeatedly press A + B when low on energy to keep it from going down faster.