Children of Time is different. It’s definitely sci-fi. It has all the familiar space tropes: laser battles, light-speed travel, planetary crash landings. But its protagonists are spiders. That’s really the only way to begin to explain the different-ness of the book.
The spiders evolve from your garden variety (yow) spiders to extremely evolved intelligent tool-using spiders. Eventually the spiders develop the capacity to reach the upper limits of their atmosphere, building space networks of space stations out of silk. This description captures only one one-hundredth of the book’s plot arc, but I share it only to support my overall review, which is: don’t read this book if you don’t like spiders.