This review contains spoilers from last year's Avengers: Infinity War (but none from Endgame, save what you could infer from the trailers).
Thanos won. He bested our heroes in Infinity War, and now half of all living creatures on Earth are dead. The surviving Avengers deal with this horrible reality in different ways (few of them positive). But it's no good reliving the past; what's done is done. Or is it?
I can't say more without spoiling things. But this film, effectively the conclusion to the 22-film saga that started with 2008's Iron Man, did a great job. It progressed the story, had interesting twists, paid homage to former films, and featured the great action and comedic lines typical of the series. It's not perfect; there are some ill-explained plot points, and like Infinity War, it doesn't stand alone- you really need to be familiar with the former movies to fully enjoy the film. But all in all, a deeply satisfying conclusion to an impressive run.
Rating: A-