Immensely satisfying but frustratingly incomplete, Avengers: Infinity War takes the MCU to darker and more surprising places than it's ever gone to before. [It's also really hard to talk about this movie in any depth without spoiling things, but fear not, this review is SPOILER-FREE.]
Thanos is coming. Tired of waiting for the Infinity Stones to come to him, Thanos takes a more proactive approach, deploying his minions across the universe to find the Stones by any means. While Iron Man, Doctor Strange, and Spider-Man take care of problems on their front, Captain America and his friends must join forces with Black Panther and others to fight a problem on that front. Meanwhile, Thor and the Guardians of the Galaxy do what they can to stop Thanos before he even comes to Earth.
Joe and Anthony Russo have continued to improve with each of their Marvel movies. The Winter Soldier was a relatively straightforward movie, Civil War had two or three narrative threads occurring simultaneously that all converge at the end. Infinity War follows the latter's cue, and structurally recalls something like The Two Towers. There are four distinct plot threads in Infinity War, each of which occasionally merge but all of which affect the others. And the script, credited to Christopher Markus and Stephen McFeely, pays off the ten-year buildup beautifully. There are huge consequences to the events in Infinity War, and some incredible surprises. Much like The Last Jedi, this is not a movie that cares about your theories, because they're probably wrong anyway. Unfortunately, and without spoiling anything, this is only half a movie. It's The Matrix: Reloaded. It's Deathly Hallows, Part 1. It's the dark crescendo that ends just before the finale, but doesn't give it to you. The fact that Infinity War is so engaging and involving despite not being the payoff most people are likely expecting it to be is laudable. But I haven't been blue-balled this badly since The Desolation of Smaug. And it's this inherent incompleteness that keeps Infinity War from being, dare I say, perfect.
Performances across-the-board are excellent. Unfortunately no one really gets enough screentime to make a huge impact, but special mention should be given to a handful of key performers: Robert Downey, Jr., Chris Hemsworth, and Zoe Saldana. As Thanos, Josh Brolin is perfectly adequate and has some surprisingly heavy dramatic material to work with, but the visual effects used to create Thanos are shockingly unconvincing at times.
Visual effects continue to be a serious issue for the MCU movies; there are some stunningly bad effects in this movie (Downey's head never really seems to be attached to his Iron Man armor...). The score, by Alan Silvestri, is incredible and easily one of the MCU's best to-date. Editing is smooth; the movie is long, but there's constantly something happening.