Wow, I enjoyed this game a lot. It was incredibly hard, though. The peripheral vision of that thing is insane. And it took me a long time to find out how to get the key in the bathroom because I didn't know that you could crouch. I also couldn't figure out the combination. The number yes, but not the reverse order. Had to look it up in one of the videos.
The controls are a bit awkward, though. E and left mouse click should be one button. It's confusing to have both for different interactions and the dialog. It should probably be E for both. Then LMT would be free to use for shooting instead of RMT which is unusual.