Taking me straight back to White Wolf's productions in the early oughts, all greyscale copies of documents and collages of notes.
Production value on this is much better, though--the various handwriting actually looks handwritten vs lifted direct from a font.
Also, after the introduction, there's nearly no external structure; the documents are laid out in the order the protagonist would have found them, but there's no pacing, chapter breaks, notes from a detached post-climax collator... It's interesting.
Heh. Shortly after I write that, I ran across a note from the curator of the notebook. Only one, though.
On balance, I really liked it. A very fast read, but solidly plotted, distinctly creepy, and with a couple of horrible moments.