Yeah, you weren't kidding when you said the game is hard. I was unable to get past the 3rd wave. Having said that I feel like the concept was amazing. I really like how you didn't just have different enemy types but each of them had their unique characteristics and were quite lethal when they appeared together. The book was a great feature too. It serves the function of both a bestiary and an instruction manual for the player.  Sound effect and art was pretty good as well.