I saw this at a preview screening in Sheffield and was blown away by the story, the quality of the acting, and the beautiful use of the Yorkshire countryside - like an extra character in the film. It gave me a strong feeling of the classic British children's cinema of the 60s and 70s - stuff like The Railway Children, Walkabout, and the work of the Children's Film Foundation - in the way that the action is really led by the (incredible) child actors, and the sense of peril is really tangible and believable. I hope to see it again on general release, and really believe that in the future it will be regarded as one of the classics of the genre.