Watched it today (may contain spoilers)
It was okay, but some parts were not faithful to the book. It was also a bit anti-climatic. However, the visuals were pretty awesome.
I wish Camazotz was creepier, though. When I read the book back in elementary school, I remember that planet creeped the hell out of me. The movie should have emphasized normal-yet-not-normal uneasiness of that place.