I like how you approached the jumpscare. It feels like the monster is hidden by the darkness, the shape is barely understandable, and all this comes from the jumpscare which has the monster drawn with scribbles. Also making the monster come from the top with its mouth at the bottom really disoriented me. This makes my imagination go crazy, trying to understand what I see. As a conclusion, this is really spooky, because I try to understand something vaguely explained.
A mini map I think could help... Not 100% sure if that's the best solution though.