Select the "Password" option at the start menu. Enter "1" until the game lets you in. Your remaining lives will display as "0". Once you die, you will have 99 lives.

Move to the left edge of the screen instead of going through one of the two doors at the "Continue/Quit" screen that appears when a game is over. You will enter a secret room that contains four extra lives. To immediately display the "Continue/Quit" Screen, press Start during game play, highlight the quit option and press Select.

During game play, find the bear's mouth in the lower part of the portrait gallery that is not a source for the small bears. Walk into this mouth to find extra lives.

Watch the game in demonstration mode. Press Start when Gomez takes an item to begin the game with the same item.

Press L + R during the opening sequence to snap Thing's fingers.

Enter the music room and wait for the music to end. The passage to the basement will now be accessible.

At the start of the game, enter the hall of stairs and move to the left. Press Up after passing the last door on the left to enter a secret door that leads to Pugsley's Den. Go through the second secret door to reach a hidden power-up room behind the stairs.