Unlock the following endings by performing the corresponding tasks:
ENDING - HOW TO UNLOCK
Bad - Leave with Kazuma after your second time through the Egg Corridor.
Normal - Complete the escape sequence without going through the Sacred Grounds.
Good - Complete the Sacred Grounds area. Make the rocket that allows access to the last cave, but do not talk to Momorin to get the booster back. Use the rocket and keep the Mimiga Mask.