Chopper Attack

Alien Disruptor:
Beat level 7 on expert mode to get the alien disruptor.

Different Views in Chopper Select Screen:
Go to a chopper but don't pick it yet. Hit the L button.
There should be a screen with statistics and a rotating picture of your chopper.
You can now use the analog stick to control the chopper's rotation.

Level Select:
At the "Press Start" screen, press C-Up seven times for level select.

Presidential Bailout:
While playing, 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.