Pause game play and press Up(2), Down(2), Left, Right, Left, Right, B, A, Start for missiles, items, and shields. Note: This may only be done once per level.
Continue game play
Quickly press Down, Up, B, A, B, A, B, A, B, A after losing the last ship on level two or higher.
Destroy the ship that appears at the end of each level within five seconds to skip the next level.