in my opion it was not the levels it was the fact that mimiku had so much sustain with baby doll eyes and (to my knowledge) the player has limited access to healing making it a bit of a slog to go through
after playing this little demo I can confidently say that is has some real promise. but i do worry that it might follow the path of other fan projects and be ridiculously difficult for no reason
I encountered a pretty bad bug with the game involving the third floor. I fainted because I didn't solve the puzzle fast enough and I still had the effects of the floor on me even in previous saves I had to start from the very beginning which was that bad but was pretty annoying.