Steven Cohen’s review published on Letterboxd :
Kenneth Lonergan's Manchester by the Sea is 2016's most devastating movie, and you can put that on the DVD cover, Amazon Studios. Allegations of sexual harassment perpetrated by Casey Affleck cannot and should not be ignored. Even with the possibility that he is a garbage person in real life, it is undeniable that he gives one of the best (if not the best) performance of the year as a man living a miserable, monastic life of isolation and self-deprivation. Upon the sudden death of his brother, Joe (Kyle Chandler), Affleck's Lee must return to his old Massachusetts home to figure out what to do about everything Joe left behind, including a teenage son (Lucas Hedges).
Through a series of flashbacks, the viewer learns just how Lee's life got to this point, and it's a testament to Lonergan's writing and his and Jennifer Lame's editing scheme that it works so well. Despite all of the tragedy floating around the film, Lonergan also fills the picture with cathartic humor, particularly in the dialogue between Lee and Patrick (Hedges), two men with almost no sense of how to interact with one another. The laughs are necessary because otherwise, this might be as punishing an experience for the viewer as it is for Lee. Even the sorrowful scenes are excellent, though, such as the final meeting between Lee and his ex-wife, Randi (Michelle Williams). The tears flowed as freely from my eyes as they did onscreen. Perhaps the biggest compliment I can pay the film is that sadness notwithstanding, a part of me still wants to watch Manchester by the Sea again. It's that good.