Shadow Gunner (PSX)

Cheat codes:
At the main menu, hold Select and quickly press Triangle, Triangle, Triangle. Then press the following codes

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

Level select:
Square, X, Square, Triangle, X, Triangle, Circle, Square.

Super gun:
X, Circle, Triangle, X, X, Circle, X, Square.

Invisibility:
Square, Triangle, X, Square, Triangle, Circle, X, Triangle.

Overhead view:
Triangle, Triangle, X, X, Square, Circle, Square, X.