Now I will preface this by saying my toaster had a hard time running this; I think it might be all the shaders. Hence, I can't give you as good feedback as someone who had the full experience. That being said: I think you really nailed the horror aspect as I was peeing my pants while playing this, granted I'm not good with horror stuff. I think it was on the third stage? The doors when you're underwater, I have a hard time understanding how they behave. They seem not to open if you're standing to close to them when the trigger for them to open hits. I didn't find any other weird behavior so the game is solid on that side. And this is my personal opinion, but the interaction box with the battery thing could be a bit bigger; you basically have to standing on it to get the battery in. Anyway, I hope you get better feedback on DD.
(the video cuts abruptly at the end because I accidentally hit the stop button, sorry)