Level skip:
Hold [Caps Lock] + [Ctrl] and press [Esc] during game play.
Unlimited lives:
Load or reset the game, then execute the following BASIC commands before running or restarting the program.
POKE 3486,12
POKE 3487,221
Unlimited lives (alternate):
Load or reset the game, then execute the following BASIC commands before running or restarting the program.
POKE 3611,12
POKE 3612,221