Chopper Attack 
Note: This game is also titled Wild Choppers.

Debug mode 
When "Push Start Button" is flashing on the opening screen:
hold Z and press Right, Left, Up, Down, A, B, Start
Then, a debug menu that allows stage select and other effects will appear.

Level select 
When "Push Start Button" is flashing on the opening screen:
press C-Up(7).

Power chopper 
At the main menu:
hold L + R + Z and press Start before selecting a chopper.

Shoot down the President 
While playing a game:
press Z + C-Up + C-Down, then launch a homing cluster at your opponent.
If it hits, you will see the president jump out of the plane.