Infinite ammunition :
Enter Triangle, Circle, Circle, Circle, Square, X, Triangle, Square as a password.

All weapons:
Enter Triangle, Triangle, Circle, Circle, Circle, X, Square, X as a password.

Invincibility:
Enter Circle, Circle, Triangle, Triangle, Circle, X, Square, X as a password.

Level passwords:

Gorgon
X, X, Triangle, Square, Square, X, Circle, X

Dimensional Temple:
Square, X, Triangle, Square, Square, Square, Circle, X

Floating Fortress:
Circle, X, Triangle, Square, Square, Circle, Circle, X

Spirit Bog:
Triangle, X, Triangle, Square, Square, Triangle, Circle, X

Canyon Village:
X, Square, Triangle, Square, Square, X, Triangle, X

Creepy Caverns:
Square, Square, Triangle, Square, Square, Square, Triangle, X

Space Ship:
Circle, Square, Triangle, Square, Square, Circle, Triangle, X

Hall Of Patriots:
Triangle, Square, Triangle, Square, Square, Triangle, Triangle, X

Graveyard Of War Machines:
Machines X, Circle, Triangle, Square, Square, X, X, Square

Nuclear Mine:
Square, Circle, Triangle, Square, Square, Square, X, Square

Launch Center:
Circle, Circle, Triangle, Square, Square, Circle, X, Square

Ulhaden Fier:
Triangle, Circle, Triangle, Square, Square, Triangle, X, Square

Garrison:
X, Triangle, Triangle, Square, Square, X, Square, Square

Inner Sanctum:
Square, Triangle, Triangle, Square, Square, Square, Square, Square