I've made it to the prison level so far. I have to say it's a pretty fun game if you get past the initial shock. The controls are learnable. The story is hard to grasp but the dialogue is charming in its own way. I think the characters interactions are very cute. The art is creative, although the hard outlines make it look bad. In fact, this game seems very art-oriented so above all I'd suggest improving the art.
I'd suggest adding more physics. It's weird how you keep momentum one way even after you jump off the ice, while the swinging pendulum you grab onto, which looks like it should have momentum, has none.
This has probably already been mentioned many times, but no music takes a lot out of the game. At first I was very creeped out by the atmosphere until the cutscenes made it clear they're not all murder victims and actually just isekai'd into a different dimension.