The monster looks cool and the doors opening and closing is a cool mechanic! The fullscreen button and how-to-play screen are nice too.
The flashlight following the mouse when standing still but the walking direction when moving was a bit disorienting, maybe stick to one? I also had trouble seeing the player, and I couldn't find a single key, so a small hint where to look would help. Also, the Exit button crashes the game on web. I had the same issue in mine, hiding it in the web build fixes that.
Keep it up!