The atmosphere is great, and really liked visuals as well. Reminds me of the old source games that I would play! Very spooky.
Maybe one thing that I would enjoy is some kind of minimap(?) that you start with, or some visual separation between the rooms. It's a little easy to get lost since the hallways etc are themed very similarity. Maybe something spooky but useful that could be added are some small lights here and there that distinguish the rooms?