Impossamole

Restore energy:
Enter JUGGLERS as a name at the high score screen.
Begin game play again, then enter ANNFRANK as a name at the high score screen.

Larger energy bar:
Enter JUGGLERS as a name at the high score screen.
Begin game play again, then enter LUMBJACK as a name at the high score screen.

Three weapon power bars:
Enter JUGGLERS as a name at the high score screen.
Begin game play again, then enter HEINZ as a name at the high score screen.

Unlimited weapons:
Load or reset the game, then execute the following BASIC command before running or restarting the program.
POKE 22281,173

Unlimited energy:
Load or reset the game, then execute the following BASIC command before running or restarting the program.
POKE 5948,173