Stealth

Unlimited lives:
Load or reset the game, then execute the following BASIC commands before running or restarting the program.
POKE 30590,173
POKE 59028,173

Unlimited lives (alternate):
Load or reset the game, then execute the following BASIC command before running or restarting the program.
POKE 23366,41

Unlimited energy:
Load or reset the game, then execute the following BASIC command before running or restarting the program.
POKE 28512,132

No enemies:
Load or reset the game, then execute the following BASIC commands before running or restarting the program.
POKE 28341,169
POKE 28342,0
POKE 28343,234
SYS 53055

Set number of lives:
Load or reset the game, then execute the following BASIC command before running or restarting the program.
Note: X represents the desired number of lives.
POKE 30298,X