The movie was a great twist on the old zombie theme: the zombies were fast, agile, engraged, and CAME AFTER YOU.
Had a very BRITISH feel to it; not just the lack of firearms, but the style of the film, the dreary outlook, the idea of toughing it out even if it's hopeless....that whole stiff upper lip bit. Very psychological film, too.
It was scary, it really was.
There needs to be more scary movies. Most horror movies these days aren't scary. Most are just stupid and excessively violent/gory.