I discovered a piece of trivia. The rectangle Hint Token always highlights the most face-down cards that it can. Therefore, when it's not doing that, it's because the Vampire card is keeping it. Therefore, you can tell which card is the Vampire! Here's one scenario:
https://www.newgrounds.com/dump/item/18c6da5297eb6f5ada311823d48446f8
Normally, the rectangle would be at the top left corner, but it's not, being at the bottom instead. So out of the three cards that it indicates, the Vampire one is known. It's the one pulling down the rectangle. There's only one option instead of three. Disregard the 9+ in the picture, although it does prove what I'm saying.
ThePhenomenon
It's one of the most brilliant games that I've played, and I have played hundreds of online games. :) Of course, it's not a work like Cactus McCoy or Larry and the Gnomes, but it's pretty clever and neatly made.