Awesome jump scare! The monster did attack me when I was near the blue gem. I haven't seen the monster before it was too late :D :D :D
I would recommend to add some very simple jump or to allow player to walk through very small obstacles. To get inside the graveyard area player has to walk around and feels like an unnecessary effort. Not sure if I missed some tactical choices here.
Another small thing I would recommend - puzzles could be different. Not a priority ofc... The one you have is clear and satisfying already!
I didn't feel the map is too big tbh (for me personally), I enjoyed it - very cosy, and old-school artstyle helps with the atmosphere!