Directed by Jon Favreau

Yes, Iron Man's back, and this time everyone knows his identity - Tony Stark, wisecracking millionaire, eccentric, and now official saviour of the free world. And doesn't he love it. So much so that he wants to keep his powers all to himself (‘I have successfully privatised world peace.') and not share the task and the glory of keeping the world a safe place - not with the military, not with the capitalists. But with power comes responsibility, and preening and acting the playboy won't do, specially when over in Russia there's a kind of Hyde to his Jekyll preparing to come and make his own claims.

Robert Downey Jr is as charmingly daffy as ever as the all-too-human hero in the suit. The mismatching of his sophisticated smart-talking urban man with the iron behemoth he becomes is still fun, but expectations are built up in those quarters of the audience looking for more than crashing metal, shattered glass and conflagrations that aren't really fulfilled, and we have to be grateful for what one-liners and witty sillinesses that we get.

This is one of those sequels where the novelty of its predecessor isn't made up for by the pleasure of familiarity - the covert relationship between Stark and his staunchly faithful but perpetually exasperated assistant Pepper Potts (Gwyneth Paltrow) doesn't quite have the crackle, the action pieces impress even less and yet again are not as inventive as one might expect. Pleasures are all from performances. Mickey Rourke, reminiscent of Yul Brynner as Genghis Khan, dons a Russian accent and an odd hairdo to brood and growl as Vanko, son of the overlooked former colleague of Stark Senior, seeking vengeance (a malign father-son influence reflected in Stark's own benign one), in the process of which he destroys the F1 Monaco Grand Prix with his stunning electric whips (hurray!). Sam Rockwell is wonderfully daft and creepy, and well-nigh unrecognisable from his likeable astronaut in Moon, as Justin Hammer, self-regarding arms manufacturer and representative of capitalism rampant. Scarlett Johansson joins Paltrow in the intelligent-sex-on-legs department as the martial artily endowed Natalie/Natasha (I was never quite sure who she actually was, but boy she can fight!) Samuel L Jackson does his unflappable elderly gravitas thing as her boss, and Don Cheadle takes over from Terrence Howard as good old principled army buddy Rhodey. Director Jon Favreau has more to do, and does it well, as Stark's hapless dogsbody. Sound cast, mostly good script, but maybe the franchise should now be put to rest.

Downey is one of those movie stars who suffers the double-edged blessing, similar to the likes of Humphrey Bogart and Cary Grant, that while being a great actor, he is really loved in most roles because he always keeps a strong element of his own persona, in his case a louche, irresponsible faux-naif smart-arse with a hint of melancholy depths. It would be good to see him try to break the mould sometime soon and play against type, and for goodness sake let's hope his next appearance will be more challenging. Two goes at Iron Man, larky though they may be, are surely enough. Let that man out!

Seen at Showcase Cinema, Middlesbrough, 1 May 2010.