Nine continues:
Pause the game and press Down(3), X, Circle, X, Circle, Triangle, Square, Triangle, Square, Up(3), Left, Right, Left, Right, Left, Right.

Nine planes:
Pause the game and press Up, Down, Left, Right, Square(2), Left, Right, Square, Circle, Up, Down.

Self-destruct:
Pause the game and press Up(2), Down(2), Left, Right, Left, Right, X, Circle.