Kill List is a really creepy and uncomfortable film. Wheatley unflinchingly shows us bleak and souless parts of Britain and the horror really comes from the realism and not knowing where the film might go next and what you might see. The 2 leads are excellent, coming off as vulnerable even though they are both powerful and deadly forces in their own right. There are many comparisons to be made to other movies but all would spoil it so I would say Kill List is best watched with no prior knowledge or expectation.