Didn't think you could get more granular than SFF. We tried to group genres together for simplicity. But some users don't seem to be liking that. All genres/categories are currently listed in the dropdown in the header.
The dropdown doesn't have Fiction, which was surprising since that's what I went looking for first. Also, when I figured out that I could click on the "Recent Fiction" heading on the homepage, I was disappointed to see that there was no way to filter down to Literary Fiction, the way most publishers do. Otherwise, all the top items are mass market fiction, which is a very different genre.