Gotta say, it was delightful to see the range on Matt Smith. He can go all cheeky and charismatic as the The Doctor, then to being creepy as hell on HOTD. He's freaking great!
It's not an absolute masterpiece like some of his comedies, but it was still enjoyable in my opinion. It's basically Edgar Wright tries out psychological horror. I just wanted to watch Matt try out being fuckin creepy and got exactly that.