Paul Deines’s review published on Letterboxd :
Astonishing thriller - the best I've seen in some time. Director Jeremy Saulnier (memo to HBO - get this guy some episodes of True Detective) has a sure hand, unblinking in the procedures of revenge and also contemplative of the pain that both drives it and is fed by it.
Macon Blair is a captivating protagonist with sleepy eyes and an intense hushed voice, forever in the high register. Devin Ratray, Amy Hargreaves and Kevin Kolack each bring a new fevered energy to their scenes. But I just fell in love with the arc of Blue Ruin, which transitions from a simple-albeit-distinct revenge plot to an unrelenting Greek tragedy. It matches Shotgun Stories and Before the Devil Knows You're Dead in its exploration of how the sins of a family repeat themselves in new iterations.
Hell, it might even match Kurosawa's Ran in that arena.
One more point: Blue Ruin is bloody, white-knuckle entertainment, but it also has some of the best dark humor I've seen outside of a Hitchcock film. One example - the extended scene in which the protagonist removes an arrow from his leg has the funniest payoff I've seen in a good while.
So, see this movie. Do it now. It's streaming all over the place. No, I don't care if it's your anniversary today - see this movie immediately.