Bonus levels:
Hold Select + Start and power on the NES console.

Hint: Extra lives:
Use a single flip to throw the ballerinas into the wall while they are spinning on their toes to earn a bonus life.

Hint: Resist magic transformation:
Play the game with two players to pass through the tenth room of a house without worrying about the magic transformation. Keep both players from losing a life and the magic will have no effect on player two.