Instant Lemming Save:
Pause game play and select the following lemming commands in order: "Turner", "Bomber", "Blocker", "Floater". When the lemmings are shot (destroyed), they will be counted as saved.
Stage Select:
Choose "Codes" from the main menu and enter the password LAMPWICK. Then highlight "End" and press X. The message "Passowrd Correct" will appear. Now choose a difficulty level and select "Play"; a statge select menu will appear that will let you start from any point in the game!
Watch Movies:
Choose "Codes" from the main menu and enter one of the following passwords:
ARMYAAA - Army movie
EGYPTAAA - Egyptian movie
MAZEAAA - Ending sequence
SPACEAAA - Space movie
When you highlight "End" and press X, the scene you selected will appear.