I found it to be very entertaining, a bit heartbreaking and thoughtful. Yes, it's a modern take on vampires but I saw it more as an allegory about what trauma does to a person and how different people choose to deal with it. Will I let the pain control me and lash out at others? Or will I find a way to move past it however difficult that may be? It's more of a suspense/thriller than horror. Worth a watch.
Review of Painkillers
