I’m honestly not even sure how to review this movie for multiple reasons. For one, there’s about a million threads happening, and it would be tedious to go through them all. Secondly, SHOCKING things happen that will SURPRISE you. Nothing will EVER BE THE SAME AGAIN. (But not really.) I would love to just give them all away, but people would be angry.
If you haven’t watched the 112 other Marvel movies up to this point (I haven’t!) all you need to know is that Thanos, who looks like Dickbutt here more than anything, has two (I think) of the (6) Infinity Stones, and is working hard to get the rest of them. His motive is to wipe out half of all living things as a cure for overpopulation.