There's not a lot I can add to from the other reviews, but there are a few main points I want to hit on. Firstly, I definitely agree with the sentiment over the color grading. There was just something off about it -- it's clear that you were intentionally going for grim, scary, whatnot, but the grade felt obvious and almost oppressive. Whatever camera you were using, it was also considerably over-sharp, and it really brought out the quality issues in the recording I think. It's tricky to make comments on the cinematography because it felt like everything about the camerawork was trying to hide what was actually happening, which somehow didn't work for this setting in a library.
The split-screen idea as a solution to keep to real time was pretty cool (not sure why you were DQed, but that part I liked), and the credits, while mayyybe being "self indulgent" were at least very eye-catching. Sadly more eye catching than the rest of the film perhaps, and that is exactly the sort of thing you don't want to hear.
I liked that you were whispering in the library. It felt real, in a film which seemed so adverse to realism.