It's a very good series, albeit a short one. The background art is beautiful, which is shown off with plenty of scenery porn. The show focuses a lot on character development and Canaan shooting people in the face. Also, the taxi driver is hilarious.
The entire series is basically constant Mood Whiplash
, having many funny/heartwarming moments back-to-back with bloody violence or heartbreak.
It's a very violent, gory show, having several scenes in which people start spewing blood out of their mouths. So if you hate that kind of thing, you probably shouldn't watch it, but otherwise I highly recommend this series.