Awe-Filled Adversaries: On level 1, stage 3, before entering into the Phantom Bat's chamber, collect an hourglass if you can find one. Fight the Phantom Bat regularly until it's destroyed. When the energy-restoring, stage-clearing crystal appears thereafter, do not collect it quite yet. When you don't collect it for a while, the stage-ending music will play anyway and the next stage will begin. Once the stage-ending tune begins, wait about three seconds and then activate your hourglass (down while jumping). If done correctly, all of the enemies on the stages thereafter will be frozen in place. They will continue to be frozen until you die or until you again activate the hourglass. (Contributed by James C.)
Money Matters: The merchants that have set up shop castle-wide will do more than just sell you goods. When you see a merchant, it's common practice to whip it repeatedly until it offers you an item. Any whipping done thereafter will bring about a different result, which may not always be in your favor. The merchant's color at the time should give you a hint:
|White: When a merchant is colored white, it can be struck without any consequence. It can be struck again and again until it turns purple and then red.|
|Purple: Before a merchant turns red, whence it'll sell an item, it turns purple. Depending on its mood when you whip it, it'll either supply you some hearts or take some from you.|
|Red: When a merchant has been struck enough times to the point where it's red, you've gotten its attention, and it'll offer you an item which you can buy or refuse.|
|Blue: After a merchant has sold you its specific item, you can uncover it again. However, whipping it now will cause it to turn blue; repeated whip strokes will destroy it for 5000 points.|
Additionally, Vampire Killer has its own twisted version of the stock market. If during a given stage you collect a white bible, the value of hearts will increase; in this case, you can buy merchant-sold items for much cheaper prices. However, if you by accident collect a purple bible, the value of hearts will decrease, and merchants will now charge sometimes-unfair prices.