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

POKE 4866,173
SYS 2096 

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

POKE 5112,0
SYS 3101 

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

POKE 5693,255
POKE 5694,255
POKE 5695,255
SYS 2096 

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

POKE 6819,173 

Unlimited points:
Note: This trick requires a joystick with an auto-fire feature. Stand on the right platform, and enable auto-fire. Points will continue to accumulate until auto-fire is disabled.