How many superheroes does it take to topple a deranged Norse god?
Roughly six, and it's down to Joss Whedon's adroit directing and a perky script that this adventure isn't a debacle. In fact, it's quite a bit of fun. Tom Hiddleston's loco Loki is hell-bent on conquering Earth and crushing his brother, Thor, but Iron Man, Captain America (above), Black Widow, Hawkeye and the Hulk (played by Mark Ruffalo, the pick of the heroes here) team up to stop him. Undemanding.