Cheat mode
Enter the options screen. Set the "Music" option to "05" and the "Sound FX" option to "21". Highlight "Exit", hold [A] + [B] + [C] and press [Start]. Shannon will say "Too easy!" to confirm correct code entry. A new "Cheater Cheater Mode" option will appear, which allows level selection, maximum lives, full energy, and unlimited weapons. Note: Only one of these options may be enabled at one time.
Full ammunition
Pause game play and press [A], [B]x3, [C], [A], [C]x2. Jim will shout to confirm correct code entry.
Extra life
Pause game play and press [B]x2, [C]x2, [A]x4. Jim will shout to confirm correct code entry.
Plasma power
Pause game play and press [C], [A], [B], [C], [A], [B], [A], [C]. Jim will shout to confirm correct code entry.
Extra continue
Press [A] + [Left] + [B], [A], [B], [A], [B], [C], [A]. Jim will shout to confirm correct code entry.