For the first hour or so, the filmmaker does a good job of showing realistic interaction between the three characters, capturing the dynamics between mother, son and father. The camera-work and editing are sensible and mature, with no attempts at flashy style to get in the way of the material, a common failing for young filmmakers (only a brief dream/fantasy shot, seemingly played for laughs, breaks this tone).
Unfortunately, in the last two-thirds the believability of the characters and their behaviour, and the focus on the power struggle between them, loses focus and gets derailed (or maybe runs off the road?). The ending not only stretches believability compared to the naturalistic tone of what has come before, but fails to fully relate to what the rest of the film was about. It certainly isn't the case that endings need to give 'closure' in the mainstream/Hollywood sense, but they do need to function as an end point for their particular stories in order to give a sense of unity, and this is what was missing here - there was no necessary connection between what happened at the end and everything else we saw happening preceding it.
