I won't say anything about the brevity of the game itself - it's a trifle, and if this is your first project, then it's quite a long game on the contrary. but, unfortunately, I have important fortunately, specific error notes. Anyway, I'm glad that at least someone else made a game for this, this manga, anime:
1) The characters are not revealed. And it would be enough to have a dialogue with surprise and joy from books in the place where there was a bookcase when there was an elevator, to have another dialogue where she is scared, and to have a dialogue character Ю about what she wants to eat. Then they would feel less dead (or vice versa, they would show a different reaction, in any case, the characters would somehow open up)
2) Do you know about the Chekhov pistol? If they write about weapons in the book, then it will definitely be used somehow. and of course, there are interesting cases when this happens consciously in order to deceive some expectations and cause some feelings in the reader. So, you caused a little dissociation. the keys are not used, and the notes do not reveal how the world works, they just tell you not to give up, you will achieve even more. Thank you, of course, for the abstract motivation, but I would like to read about people. any story about people
and the 3rd, non-essential) I wouldn't make enemies in such a universe
Anyway, thank you for your work! It was fun to play