Asteroids Codes -

Excalibur ship:
Hold Select and press Triangle, Circle(2), Triangle, Square, Circle, Square when "Press Start" flashes at the title screen. The sound of an exploding asteroid will confirm correct code entry.

Level select:
Hold Select and press Square, Triangle, Circle, Triangle(2), Square, Circle when "Press Start" flashes at the title screen. The sound of an exploding asteroid will confirm correct code entry. Then, press Select + Start during game play. Use the D-pad to select a new level and zone, as well as toggle collision detection. Press L1 to resume game play.

Original Asteroids mini-game:
Hold Select and press Circle(3), Triangle, Square(2), Circle when "Press Start" flashes at the title screen. The sound of an exploding asteroid will confirm correct code entry. Press Start and select the "Classic Asteroids" option on the main menu.

Extra life (Original Asteroids mini-game):
Press Start to pause game play, then press Up, Down, Left, Right, Circle, Square, X, Triangle.

99 lives (Original Asteroids mini-game):
Press Start to pause game play, then press Up, X, Down, Triangle, Left, Square, Right, Circle.

Invincibility (Original Asteroids mini-game):
Press Start to pause game play, then press Down(2), Up(2), Circle, Square, Triangle(2).

Hint: Easy Armageddon:
Hold Fire for approximately five seconds for an Armageddon without collecting the corresponding power-up.