Automatic movement and firing:
This will work until player makes a movement and fires a shot. Type this inside a game level and press return: robot

Create a Centipede nearby:
Type this inside a game level and press return: pede

End current level:
Type this inside a game level and press return: goto

End game and go back to the desktop:
Type this inside a game level and press return: dload

Fly Mode:
Type this inside a game level and press return: fly

Infinite Lives:
During gameplay, enter this code and hit ENTER: getalife.

Normal Game Speed:
Type this inside a game level and press return: normal

Slow Game Speed:
Type this inside a game level and press return: slow

Slower Game Speed:
Type this inside a game level and press return: sloww

Slower Than That Game Speed:
Type this inside a game level and press return: slowww

Slowest Game Speed:
Type this inside a game level and press return: slowwww