(CNN) Having set up a formidable task and then some with the finish of "Infinity War," "Avengers: Endgame" rises to the challenge, delivering an epic finale that proves immensely satisfying. Without being too grandiose, it also feels like the culmination of everything Marvel has built in conquering the pop-culture universe.

"Endgame" is a massive undertaking in more ways than one, in part because "Infinity War" essentially constructed a giant jigsaw puzzle, then left it unfinished.

Running just over three hours (in a manner that mildly tests patience in the first hour, and bladders in the third), the sequel has more on its mind than just completing that story. Somehow, the film manages to set up Marvel's future while nostalgically embracing its past, bringing a sense of cohesion to the decade-plus roster of movies that have led (remarkably, if you think back to "Iron Man" in 2008) up to this point.

Give considerable credit to brother team Anthony and Joe Russo, who, coupled with their two "Captain America" movies and now this two-part epic, have directed roughly 10 hours of the most robust action that Marvel has conjured. They have done so, moreover, with as much attention to character in the screenplay by Christopher Markus and Stephen McFeely as the pyrotechnics and heroic crowd-pleasing moments, although rest assured, there are plenty of both before "Endgame," well, ends.

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