I'll give the positives first. This movie has a dark tone to it, and doesn't stray from the mood that it establishes early on. Also, there are some good performances by Anna Walton, Sean Pertwee and Ron Perlman.
On the negative side, the events in the storyline are somewhat predictable, and the most of the characters aren't developed in any meaningful way... but this movie isn't a drama, it's about action, so maybe that isn't important, depending on what you're looking for.
This is one of those movies you don't want to come upon with high expectations. My suggestion is to not take it too seriously. At its basic premise there are monsters, and our heroes must defeat those monsters. If you like monster slaying on a ravaged world, then this may be for you. If you want solid stories and deep characters, you may be disappointed.