I think I found a bug in the room with the purple dust. If the monster catches me the screen goes black and some text is displayed about it being too big, but with no CG. Once the text finishes the game room reappears with Kana naked in the area where the monster was trapped. The monster itself is frozen and can't be interacted with, and leaving the room does not help. I am using the most recent version of the game and here is a copy of the relevant save.
Edit: Re-downloaded the game and started a new game, same issue.