Carl Sandell’s review published on Letterboxd :
Every aspect of the movie feels just right, from the score that seamlessly mixes with some strong pieces from Händel's The Messiah to editing that is at times entirely erratic to illustrate how difficult it is for the protagonist to stay in the moment instead of disappearing into a flashback.
Among such greatness Casey Affleck's performance still sticks out. He doesn't just manage to make this kind of sad brooding man sympathetic and interesting. The real strength is that you can absolutely see that the character is the same person in the present and in flashbacks, but with a devastating void inside. He still interacts with people largely in the same way, but it's all surface. It's special to get that nuance through the screen, although he is aided by a script with some real gut-punching lines that get more heartbreaking the more they sink in. And it feels like an honest exploration of grief and remorse without falling into a trap of simplifying repentance.