Cheat mode:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 5806,234
POKE 5807,234
POKE 11839,10
POKE 5808,234
SYS 2640 

Unlimited lives:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 5806,234
POKE 5807,234 

Invincibility:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 3237,169
POKE 3238,0
POKE 3239,234
POKE 5765,169
POKE 5766,0
POKE 5767,234