The Marvel universe is so damn weird. I don't understand how mythical gods and aliens and ordinary assassin types are supposed to exist in the same universe on a reasonably level playing field. I don't understand what S.H.I.E.L.D. is or who, exactly, it's supposed to have jurisdiction over. I don't understand the logic of the interdimensional portals—if there is any logic. But whatever. Writer-director Joss Whedon finds exactly the right tone for this nonsense, neither acting above it nor trying to puff it into something more serious than it is but simply embracing it in all its goofiness.
He meanders a bit, perhaps inevitable in a story about how disparate individuals come to unite around a common cause, but the journey is colorful and clever and fun. Classic cinema it's not, but with its endearing sketches and witty banter, The Avengers is better than it has any right to be.