Finish the game having collected all the special items to see the alternate ending.
Hidden Level
The hidden level is in stage five. After you beat the first boss, a jumping demon creature, you must go through the doors to get to the next screen. There will be two paths: up and to the right. As the right leads to an empty room, go straight up but stay to the right. There will be an opening in the wall leading to the next screen. This screen will have two bats hanging from the ceiling with a platform below. Below this platform is another smaller platform, which is over the hole in the floor. Jump down this hole. While falling you will see a candle: whip it. After you get the 1-Up candle, you will land on a platform. On this platform will be a white candle: whip this then proceed to get off the platform. Do not exit the room. The floor below will disappear. Jump through it to get to the hidden level.