An excellent but far from perfect culmination of ten years' buildup; I would call this about the sixth best MCU film, as its extremely busy narrative both ratchets up the stakes and undermines the achievements of previous entries, with a lot of Because Plot happening, and far too much sound and fury in many action setpieces to make them anything other than noise. I will echo what many others have said before me - Thanos's "idealistic" goal is nonsensical, and the conversion of one of Marvel's most hideous classic villains into a rather stupid attempt at a "well-intentioned extremist" is a distinctly flawed effort (more than anything else about the two-part story, this is what we needed Endgame for, as the version in that film actually comes across as a "bad guy", instead of the weirdly half-sympathetic one we see in this film). It has a lot of strong elements, but could definitely have been improved upon. Still, at the end of the day, it's an Avengers film, and all but one of those has been in the 99th percentile of awesomeness compared to everything Hollywood has ever produced. Do see it, but expect some frustrations.