It may not appear so at first glance, but this is a Lynne Ramsay film through and through -- a heart wrenching, hyper-violent addition to her oeuvre of films focusing on the individual's psychological response and post-traumatic path subsequent to their environment's introduction of an unexpected and uncontrollable tragedy. Morvern Callar, We Need to Talk About Kevin, and You Were Never Really Here could almost function as an unofficial trilogy dealing with said theme, exploring lonely, singular minds' reactions to larger, more macro-level issues such as the suicide of a loved one, the parenting of a psychopath and the abduction & exploitation of children.
Joaquin Phoenix sinks deep into his role of the enigmatic Joe, a war veteran and former member of the FBI, tormented by all that he's seen, having made it his mission to protect, at all costs, those being taken advantage of by wealthy American institutions. He gives close to the strongest male performance of the festival, second only to Robert Pattinson's manic tour-de-force in the Safdie Brothers' Good Time. And Jonny Greenwood composes his "most Radiohead" score yet (no complaints here), a slightly more abstract departure from his previous efforts.
At only 85-90 minutes, the runtime flies by; I wasn't exactly left craving more -- the film is far too heavy for that -- but I would be curious what a ten to fifteen minute longer cut of this would feel like. Then again, the sharp cutting and scene chopping (particularly during the more visceral/physical sequences), resulting in a great deal of off-screen violence, are part of what makes the film's brutal energy so effective, and more so a subversion of than an addition to the action-revenge sub-genre.