Ooh, this was simple and fun imo. I was surprised very early on by a burly man, and then the second time I made it out, although very narrowly. I do notice, it looks like you may have run into the same issue I did when trying to get Unity to function within a true "pitch black" scene. Unity is a bit irritating in this, it keeps adding little lights and shadows in places that you may not want, sometimes only adding them at the last second when entering playmode. I had to do some research on this to achieve the darkness I really wanted in my game, and it still kept doing it on occasion. It was very irritating.
Also, I recently acquired and am playing through a free copy of Amnesia: the Bunker from the Epic store. A possible inspiration? A very smart one imo. Well done with this!