You can use one of the following codes during the game:
Ultra Hard Difficulty: X, B, A, X, Black
All Planes: Y, X, B, Y, Black
10 More Tokens: X, B, X, B, Black
Guns with 1000 damage: B, X, A, B, Black
$5000: A, Y, A, Y, Black
Invincibility: Y, A, X, B, Black