Interesting movie, but far from a total success. The director uses his camera cleverly and executes some fine visual tricks, but they don't lead anywhere, because the film has such an "one-joke" premise and a repetitive script. Great music score, astonishingly mature work by the boy who plays the central character, a few scares at the end, but the movie still rings hollow, and gets no more than a 6/10 from me.
