Enter these cheats on the title screen, before the Demo appears.

Effect	Code
Magic Doors can be accessed even if you lose a life or a continue.	Fire, Jump, Fire, Jump, Fire, Jump, Right, 1P.
The title screen will display "POWER UP" along the bottom. You will play through the game with the effects of the blue and yellow candy.	Left, Jump, Left, 1P, Left, Fire, Left, 1P.