Gauntlet

9999 health points:
Begin game play in two player mode and intentionally allow player two to be killed by Death. Then, allow player one to also be killed by Death to increase your character's health to 9999.

No walls:
Pause game play and wait for at least three minutes.

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

POKE 49009,96
SYS 32768

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

POKE 48621,96
SYS 32768