Ex-Mutants

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(3), C, A, C(2).
Jim will shout to confirm correct code entry.

Extra life:
Pause game play and press B(2), C(2), A(4).
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.