After the intro stages, Stage 1: Ruins normally leads to Stage 2: Sky (similar to the dragon's intro stage). However, you can jump directly to Stage 7: Bubble Cave (with the vanishing bubble platforms).
When fighting the Stage 1 boss, after he transforms into the giant demon, finish him off with the mouse's bombs. Only the final hit matters, so you can weaken him using the other characters' attacks.
The easiest way to land a bomb hit is when the demon steps back to charge his seeking orb attack. Quickly lay bombs just ahead of where his front foot was, and he will step forward into the explosion as he attacks.
Contributed by: Kapow751
Restore Energy
At very end of the game on Normal mode, on the screen with the castle image and flashing light show, press Up, Down, Up, Down, Right, Left, Right, Left, A, B, A, and B. The effect will result when you start another game.
Contributed by: KeyBlade999
Level Passwords (JP Version)
Enter the following passwords to continue at the desired level:
Contributed by: German Dragon
Music Room (Japanese version)
Effect
KAZU
Effect
Music Room
Contributed by: ReyVGM
All Passwords
Passwords are 4 letters long. 1st is easy mode, 2nd is normal: [EASY | NORMAL].
Passwords with an asterisk (*) are hidden passwords not shown during gameplay. The password function uses a list of valid passwords rather than calculated results, so every password in the game is listed here.
No password exists for Stage 4b: Crab Ride. This is accessed by falling down the waterfall during the Stage 3 boss battle.