The game overall is pretty nice! There are just a few critiques I have of things that kept this from being a 5/5:
1. Check your sentences. There are some words missing in the dialogue and some of the structure just doesn't make sense. perhaps you aren't a native English speaker?
2. As mentioned before, the book puzzle doesn't seem to have any clues to it. You either have to guess or look up a walkthrough. Kind of ruined the game for me.
Other than that I thought it was a good game. I am ok with the boss fight, though it maybe could have had less distracting flashes. Good job, Can't wait for #3!