Bonus level:
Destroy all of the ships in the first wave in level two. Destroy the first ship in the second wave, but avoid all the others. The ships will explode and the bonus level will begin.

Invincibility:
Pause game play and press Triangle(2), X(2), Circle, Square, Circle, Square, Down, Left. A sound will confirm correct code entry. Repeat this code to disable invincibility.

Full power-ups:
Pause game play and press Up(2), Down(2), Left, Right, Left, Right, X, Circle. A sound will confirm correct code entry. This code may be repeated as needed.

Level select:
Press Square(5), Triangle(7), Circle(3) at the title screen.