It was quite good. It was very tense when they were hiding under the bed and in the wardrobe, I would have died on the spot and wouldn't be able to move if I'd been in that position.
I think the weird people burning down the wooden tower was a bit predictable, and jumping into a tree isn't very realistic. I could believe it if one of them managed to do it, but all 3 just wouldn't happen. Also when they were looking out of the tower windows you could tell the horizon was created digitally and wasn't real, which was a bit distracting.
Was the guy at the petrol station related to the weird people? I imagined him taking over from them after they all died, I don't think it was realistic for that laughing guy to have survived being slashed with an axe and burned.