The twist (if you can even call it that) is transparent at the start of the film - I don't think it was intentional. It certainly doesn't play its cards close to its chest. Once you realize it, it makes the whole thing anticlimactic, and the built-up tension goes to waste when it doesn't peak with the reveal in the third act. Especially since it doesn't offer any insight into the brothers' kinship and the grief that comes with a brother losing his twin, which makes the violence and the story seem rather barren and trivial.