This is a high-quality sequel with intelligent contributions from the writers, actors, and director Joss Whedon. The development of the characters, from Samuel L. Jackson's one-eyed, growling Nick Fury to Chris Evans idealistic Captain America to Robert Downey's smart-aleck Ironman learning to play well with others, reflects what made Marvel special in the first place. The action scenes are like seeing a big, graphically rich comic page come to life. And it's not just action; there are quite unexpected plot twists. My only caveat is that the bad guys' motivation seems a little thin (apparently they're just bad). Loki seems to suffer from the conventional movie-script father conflict (yawn). But, after all, the good guys are the main attraction, and they're -- well, super!