The Avengers have been assembled and, for the most part, they fit together superbly. A joyous blend of heroism and humour that raises the stakes even as it maintains a firm grip on what makes the individual heroes tick.
The bad news is that if you haven't seen "Thor," "Captain America" and "Iron Man 2" - that's six hours and three minutes of homework - The Avengers won't make sense. The good news is if you're a human under the age of 45, you probably already have.
Henry BarnesThe Guardian
It's fun to watch Whedon pitch his heroes against each other. Child's play, maybe, but entertaining all the same.