I found another bug. I was fighting the boss, and because I had the upgrade that increases the range that you can pick up the knife, I was able to just stand next to him and attack endlessly, killing him quickly. Unfortunately, this made him get stuck in an endless death animation, and I was unable to continue the game. Maybe if you made it so that the boss moved as soon as he got hit, it would stop that from happening? I'm not really sure what caused it, though.