OH MY GOD AVENGERS I CANNOT EVEN WHERE IS MY MIND IN A FRILLION BROKEN PIECES OF ACHEY GOODNESS DAMN YOU JOSS WHEDON
*flop*
ETA: To quote
likeaduece, who's far more articulate than I, "I can't think of any significant storytelling thing I would have liked to be different [...]I was surprised overall by how mature the film's idea of heroism was."
ETA 2: Possible spoilers in the comments.