The Book of Skulls

Is this science fiction? Is this fantasy? Is this pure social commentary? The author seems to think it's scifi, apparently so did hundreds of people who submitted the book to Hugo and Nebula awards. It never feels very scifi, but it has some themese, like the author says. The book is overall very interesting and a good read. There is a rotating point of view, which works very well. The build up and back story to the book is quite extensive and then when the gears start turning the book goes quite fast. I recommend.