Invincibility 
Circle, Circle, Triangle, Triangle, Circle, X, Square, X.

All weapons
Triangle, Triangle, Circle, Circle, Circle, X, Square, X.

Infinite ammo
Triangle, Circle, Circle, Circle, Square, X, Triangle, Square.

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 		X, Circle, Triangle, Square, Square, X, X,
War Machines		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

Thanks to Revolution readers G-man, chipathy, Vinnie, Brian, shaun, Chris McClain, Cmiller, and Grey_Fox!