The use of keys as weapons / Item Crashes, followed by a question mark from your character. Doubles as a Moment of Awesome if you manage to defeat Dracula only using it as described above.
An area that involves traversing a staircase of Fleamen riding metal balls ends with the exit to the tower on one side, and the source of the fleamen on the other. Making your way up there with just the right jump will allow you to see a burly ogre man whose sole purpose is to load the orbs (with fleamen pre-applied) onto the path after they've hit the end of the path down below. Apparently Dracula is a firm believer in recycling.
Maria's ending is far more cutesy, and serves as a hilarious Mood Whiplash compared to the rest of the game.
Just the idea of Dracula being beaten to death by a young girl throwing birds as weapons.
If you tried to play the original version of the game with the wrong system card, it wouldn't just display a boring error message like most games, but rather load up an entire joke minigame called Akumajyo Dracula Peke. It must be seen to be believed.