Ah, this book is a messy quilt of genres. It is about a city that is a messy quilt of species, cultures, and environments and one of the characters is a walking messy quilt of random multi-specie body parts. Fractals, yet never using the word fractal.
Mieville easily gets away with many things in this book that I would complain about if attempted by someone else. The execution is so perfect, I feel honored to read it.
And just when I think I get where he's going, he punches me in the face with another cool thing.
Art is about something new and appropriate for the time. That is exactly what this book was and is.