Alien Disruptor:
Beat the game on Expert to get the disruptor. 


Debug mode: 
Hold Z and press Right, Left, Up, Down, A, B, Start when "Press Start" appears
on the opening screen to access a debug menu.


Eighth Level:
The secret eighth level is accessed by finishing the previous seven levels on 
the "Hard" setting. 


Shoot down the President: 
Hold Z, C-up, and C-down during game play, then fire a homing cluster at an enemy
plane. The president will jump out if the H-Cluster hits.