I'm not sure enough punches were thrown. The Avengers (does this really count as a spoiler?) fight bad guys and then each other and then hordes and hordes of more bad guys, such that there are virtually no punch-free frames. And still, I walked out of the theater thinking I was maybe 10-15 punches shy of getting my money's worth.
More seriously, it's okay for what it is. I find the franchise wears. I still basically like the characters and I appreciate the patriotism and overall wholesomeness (though a couple of swear words and sexual innuendos creep into this one, parents of little ones), but there is still nothing at stake, as a commenter said of a previous installment:
Nothing is really at stake. None of the heroes can die, so they are not really risking anything. I understand they’re all theoretically mortal, but within the movie’s context they’re indestructible and therefore, in the end, boring. (Though the movie was fun while it lasted.)”.This is the most quasi-religious of the installments, w/ a cameo appearance from Pope Francis and