Andrew Rogers’s review published on Letterboxd:
Started out having a good time with this thinking, "what's everyone on about with this being annoying? Pitt is great here! He's funny and I'm having a fun time!" Then the Aaron Taylor-Johnson and Brian Tyree Henry characters get introduced, and the Joey King character not long after...
Tyree Henry isn't bad, Taylor-Johnson maybe isn't as bad as much as I'm mildly allergic to him, and King is godawfully enervating. King's character essentially only exists so that Michael Shannon only had to be on set for a week rather than the whole shoot, and while Shannon goes for it as a Russian raised in the Yakuza only to slice his way into independent power, it's not worth the wait. Long, long, looong scenes with BTH and ATJ's characters are bulky with unclever repeated bits (e.g. "I'm Lemon, he's Tangerine" "Like the fruit?" which isn't even a joke yet is repeated maybe six times as if it's the funniest thing ever). There are moments where I buy into Lemon and Tangerine's relationship, and a couple of the Thomas the Train Engine jokes work, but for the majority of all non-Pitt scenes one is left wondering when we can get back to Pitt.
Because Pitt is coasting on charm in the best way, effortlessly funny in a character with an interesting dynamic: an assassin in a cartoon world trying to choose nonviolence. He's the one who makes the fights distinct, as he's not fighting to win or kill—he's fighting to stop fighting, bumbling in a drunken/clumsy martial arts way, and yet he can't help from winning/killing. It's so thuddingly obvious that THIS is what the movie should be! Pitt in wry mode tripping into fistfights! Instead of letting Pitt's effortlessness guide the film, it works sweatily to try and make this a sweeping story and wring cheap laughs out of cameos. Staheklski >>> Leitch.
PS On the cameos: Tatum was funny at first but then they keep cutting back to him. In my mind the point of a cameo like that is that it's one quick thing, cutting back to more of his reaction shots is desperate. Then you have Zazie Beets and Sandra Bullock, who are credited but whose roles are glorified cameos that make you wonder why they're in this at all. Ultimately the only one that works is the one I'd peg as least likely to work on paper: Ryan Reynolds as Carver, the assassin who was supposed to be on the train. Because his is very short and then left alone, the way a cameo is supposed to work.