Saw this at the Rotterdam Film Festival (IFFR) 2017, where it was nominated for the Tiger Award (but not awarded). Very original plot, unusual developments and it got much more complicated than the synopsis on the IFFR website already hinted to. The unexpected turns of events seem inexhaustible, but as soon as you think you've seen them all, a new unexpected thing happens.
It did not bother me that the original setup seemed a bit far-fetched. It became still more surprising after the sister was shown that he filmed everything, that she nevertheless knowingly kept the camera intact. The whole sequence of developments was compelling and there was not a single boring moment.
During the final Q&A, the director told he had ideas since a very long time about a movie that a someone makes for himself and not to show anyone else. He had a lot of friends telling about their private video's, out of which stories he got more ideas that were incorporated in this film. Second idea was pushing someone past the limit. Third idea was a confrontation with your background, your family and everything else that determines where you come from.
Finally, as a side remark, I noticed the very original format for the final credits. It started as a blue B-movie with a naked man and woman on a beach, suddenly changing into credits rolling by in an old-fashioned type cast. It was not obvious to everyone in the audience that this indeed were the final credits, until someone started an applause after which everyone got it that this was the end. It was a nice deviation from the seemingly endless credits that come after most movies, meticulously quoting everyone involved in the film making until the last caterer and chauffeur.