Enter the following codes quickly at the ‘Press Start’ screen:
Goodies option:
Press Triangle, Square, Circle, Left, Square, Triangle, Square, Circle, Left,
Square. Go to the ‘optioons’ menu to find a new selection.
Nakomi mode:
Press Up, Up, Down, Down, Left, Right, Left, Right, X, Circle.
Big head Player:
Press Square, Circle, Circle, Square, Up, Square, Circle, Circle, Square, Triangle.
Big head Aliens:
Press Square, Circle, Circle, Square, Up, Square, Circle, Circle, Square, X.
Speed run:
Press X, Square, Triangle, Circle, X, Square, Triangle, Circle, L2, R2.
Grayscale graphics:
Press X(2), Triangle(2), Square(2), Circle(2), Up, Down
Sepia Graphics:
Press Left 10 times.
GameShark Codes
Have All Weapons P1300936810003 300936820003 300936830003 300936840003 Infinite Ammo P1800936b60006 Infinite Lives P1800936bc0005
Thanks to Revolution readers Kent and Mr. Pickit!