During gameplay press [F9] to bring up the console then
enter a code below and press ENTER to activate:

Code               Result
--------------------------
next level       - Skip level.
god              - Invincibility toggle.
set damage 0     - No damage.
destroy all      - All opponents dead.
load level #     - Load level put in 1-99 for #.
set bullet #     - Get # amount of bullets.
set missile #    - Get # amount of missiles.
reload level     - Restart level.
set dc #         - Get # of Depth charges.

Note: (Put in a number for #)