Nice atmosphere, i like the concept and the game loop itself is easy to figure out and enjoy. I think more animations on the gate or some sort of HP bar that would indicate that you have to kill enough books to get to the tome would have been helpful, the first level I just bashed against it while killing a couple of enemies and i though the bashing was the reason that i passed (though maybe its a me thing haha). I like the game, you did a good job on it!