At its best moments, Avengers: Infinity Wars taps into that pure joy. It's like a crossover episode in the best ways, like when the ego of Tony Stark (Robert Downey Jr.) butts heads with Dr. Strange (Benedict Cumberbatch), or when Thor (Chris Hemsworth) strikes up an unlikely friendship with Groot (Vin Diesel). When you have a story like this that comes as a culmination of 20 movies and too many characters to keep track of, the story has to skate thin on character development and focus on the chemistry or tensions of the different mashups.
The latest Avengers movie comes with the highest stakes yet, finally featuring a formidable Thanos (Josh Brolin) whose presence has been steadily built up (mostly in the stingers) from previous Marvel movies. He's on a mission to collect all of the Infinity Stones in order to accrue the power to destroy half the universe. Half the universe is neither a generalization or an exaggeration. Thanos believes that the universe has a finite amount of resources and they are too scarce to go around. His solution is an indiscriminate genocide of a random half of the universe to make sure that everyone can live with full bellies.
The Marvel universe has had its fair share of forgettable villains -- you'd be commended for even remembering half of them -- and Thanos is a funny one. He's allowed more development because arguably the film centers around him - his journey to collect the stones, his arc and his tribulations. However, he's so matter-of-fact, he's not that interesting. He's so single-minded it's admirable but it doesn't make for compelling storytelling. It doesn't help that his emotion depends largely on the effectiveness of his purple CG face, although there could be no better man to try than Brolin.
The usual complaints of the Avengers mashups remain, in that characters get lost in the mix. Some exceptions include Thor, coming off of Ragnarok with aplomb and both Spiderman (Tom Holland) and Wanda (Elizabeth Olsen) provide a needed emotional core. With so many characters and the resulting minimized screen time, it quickly becomes clear who has acting chops and doesn't. Cumberbatch is convincing with every word, whereas you can't help but wonder if they had to pipe eyedrops into Chris Pratt's eyes to conjure his emotion. However, story-wise, Black Panther (Chadwick Boseman) is essentially only there to provide soldiers for a slaughter and we get no chance at all to absorb the impact Captain America: Civil War has had on a much-hardened Steve Rogers (Chris Evans).
As a two-parter, Infinity Wars has the inevitable misfortune as a set-up movie for the finale. We can't expect a resolution, nor can we really expect a full character arc for anyone involved. The way the story is set up however, the biggest fault is the lack of stakes. Although Infinity Wars starts off with a bang, by the end we're no longer feeling the effect of the losses and we lose the emotional impact of the destruction. Furthermore, at this point in the Avengers queue, it's hard to keep feeling frustrated at how ineffectual some of the team members are at working together and it's tiring how often they're the source of their own failure. How big does an ego have to be to supersede the fate of the universe?
Infinity Wars also suffers from a muddled theme. As said before, Thanos has a focused intent and is all too ready to sacrifice in order to achieve it. This is juxtaposed against the different members of the Avengers who are constantly given choices throughout the movie to sacrifice something for the greater good. It's very clear that a theme was meant to be established there, but not entirely sure what it's meant to say because there is no consistency in what they say, do, or what results. Perhaps we'll get a clearer answer in the sequel and the conclusion to this arc of the Marvel universe.
However, these are minor quips in the scope of what the film needs to accomplish. Avengers has always been about the threat of a villain too large to defeat alone and the fun of seeing everyone come together. The Marvel universe has always been good at balancing humor with drama, and that's what makes this an enjoyable romp albeit not one meant for constant rewatches. Some of the more weakly written characters get lost, but there's undeniable entertainment in getting to see your other favorites again. The most you can ask is for a rollicking good time and a true sense of the danger the heroes need to save us from. It's a movie to laugh to, gasp at, and cheer for. Grab a large bag of popcorn and enjoy the ride.
On a final note, the Avengers movies have come out every three years, and they've each marked a sort of different stage of my review writing for films. Here are the previous ones, just for fun:
Avengers: Age of Ultron