Your game has a nice The Room vibe to it. :)
Owning quite a few bookcases myself, I would recommend adding some book-ends and artifacts to some of the shelves -- especially the empty ones. Although most people stack books as you already have shown, sometimes you'll see books stacked on their sides going vertically or propped up with the cover of the book facing the viewer.
The curved middle board is a little confusing. It looks like a desk of sorts, but there's no visible chair to sit in or other things you would expect to find at a desk, like scattered pieces of paper and various writing utensils. If this is mean to be strictly a bookcase, I would get rid of the curved, desk-like portion and just make it all more like a bookcase.
The close-up models of the books look really good, especially the ones that look a bit worn.