Unlimited bombs: Pause game play and press I, II, Left,
I, II, Up, I, Down, I,
II, Select, Up, Down.
Unlimited ammunition: Pause game play and press II, Left, II,
Up, I, Right, I.
Nine credits: Enter sound test option and play the following songs
(in order): 0, 3, 3, 8, 3, 9, 0, 0, 8, 0.
Unlimited credits: Enter sound test option and play the following songs
(in order): 3, 4, 3, 8, 0, 1, 4, 1, 14, 14.
Maximum HP: Enter sound test option and play the following songs
(in order): 3, 7, 3, 5, 1, 8, 2, 1, 9, 8, 4.
Arcade mode: Enter sound test option and play the following songs
(in order): 7, 7, 7, 7, 9, 3, 10.
Start at second half of game: Enter sound test option and play the following songs
(in order): 1, 6, 0, 10, 5, 2, 10, 3, 8. Game play will begin
after powering up with heavy artillery and speed.
Fast mode: Enter sound test option and play the following songs
(in order): 7, 5, 8, 4, 1, 10, 5, 1, 10, 5, 1, 8.
