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

POKE 34401,169
POKE 34402,1
POKE 34403,234
SYS 36861 
Cheat mode (alternate):
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 34401,173
SYS 36861 
Cheat mode (alternate):
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 34401,169
POKE 34402,1
POKE 34403,234
POKE 34404,0
SYS 36861 
Unlimited lives:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 34404,45
SYS 36861 
No enemies:
Load or reset the game, then execute the following BASIC commands before running or restarting the program. 

POKE 40537,141
SYS 36861