Shot in 3D, the third blockbuster about Marvel Comics' Tony Stark – inventor, industrial tycoon, bionic man and superhero – is a loud, overlong, oppressively violent tale of saving the world from yet another megalomaniac.

Shane Black, a bright, experienced screenwriter directing his second movie, is an anonymous leader of a vast technical army, and the film's saving graces are Downey's Stark, a charming neurotic; Rebecca Hall, an old flame who seems to have taken a wrong turn but is infinitely more engaging than Stark's tiresome current girlfriend Gwyneth Paltrow; and especially Ben Kingsley, a big surprise in every sense as the villainous "Mandarin", his best performance since Sexy Beast.