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

POKE 28768,234
POKE 28769,234
SYS 28672 
Invincibility:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 28768,175
POKE 36617,6