Ear Worm: Full of bouncy music and more atmospheric pieces as well, this track in particular, which plays in Batland Castle (the first real dungeon of the game, which you will spend a great deal of time in) instantly sets the mood for the rest of the game and is impossible not to be left in your brains for years to come.
Also the boss battle theme is incredibly vibrant and exciting. A wonderful remix exists here.
Good Bad Bugs: The final boss is, rightly so, the hardest boss of the game. However, most of his attacks are geared to hit you if you stand in front of him. It's very easy to confuse the AI by going behind him and placing his throne between you. With that set-up, half of his attacks won't be able to hit you, and the rest are easy to dodge. He'll also stay nicely in the same spot for you to throw your hat at him.
Sequel Displacement: This game is the sequel to an obscure Japan-exclusive PC Engine platformer known as Makai Prince Dorabochan.
It's Short, so It Sucks: Including the training island, there are only five levels in the whole game, all of which aren't that big.