It was only available for a very brief time in theaters, but fortunately you can watch it now.
It's interpretation of zombies, as the degraded subject, is excellent but there's little analysis to do. It's so straightforward that reviewing it would be like the clown car theory of mockery. Just go watch it.
(Do you see the muzzle on the child in the poster? There, you've captured the entire movie in a nutshell.)
What's funny is that the other big work by Mike Carey, was the comic Lucifer.
Which was also translated, into the pseudo-detective television series Lucifer.
Whereas this interpretation is the complete opposite, throwing out the major storylines and the sacred tone of the comic for something completely different. And it is glorious. Lucifer here is a sort of super-slick deity in the sense of nothing in the world affects him, and he only intervenes out of a sense of boredom. It's a detective show where half of every episode is spent convincing the Deus ex Machina to even care. I don't even know what I'm watching, or that I could recommend it, but it's different in a totally fantastic way.