It was a breath of fresh air against the dark, brooding likes of Batman and its success allowed for Marvel’s ambitious Avengers project to become a reality. 2010’s Iron Man 2 should have continued in the same vein, but unfortunately wound up a dull, muddled mess. Over-crowded with sub-plots and ancillary characters, it’s probably the weakest Marvel film to date.

With Avengers Assemble proving a box-office behemoth and a critical success, the hopes were high that Iron Man 3 could set Stark’s franchise back on track. With director of the first two instalments Jon Favreau stepping back, Marvel went with the somewhat leftfield choice of director in Shane Black, the man who scripted Lethal Weapon, and Downey Jr.’s Kiss Kiss, Bang Bang.

His appointment proved to be an inspired choice, as Iron Man 3 is comfortably the best stand-alone Marvel film.

The plot sees Robert Downey Jr.’s Tony Stark take centre stage again, as he finds himself facing off against sinister extremist The Mandarin. Stark is plagued with insomnia and anxiety attacks after his experience carrying a nuke through a wormhole during Avengers Assemble, and while he’s still his motor-mouthed, witty self, he’s a lot more human than we’ve ever seen him before.

Iron Man has always been an extension of Tony Stark, and here that idea is explored in depth by Shane Black and Drew Pearce’s script. As Tony’s state of mind deteriorates, so too his current suit malfunctions and operates at less than optimum capacity. At one point he very literally has to carry the baggage that Iron Man has given him, dragging the suit behind him like the emotional weight he can’t shed. As a result, he has to do more fighting as Tony Stark, rediscovering the brilliant scientist and engineer that we know him to be.

The action throughout Iron Man 3 is exemplary; the destruction of Stark’s iconic Malibu home is breathtaking, while a mid-air rescue is both an exhilarating and – rare in this day and age – a genuinely innovative sequence.

As good as Robert Downey Jr. is here, his film is stolen out from under him by Ben Kingsley as The Mandarin. Kingsley’s performance is a multi-faceted one, and it’s sinister, funny and always hugely entertaining. It’s an unforgettable role, and if it’s one that might rankle some of the die-hard comic fans, it’s one that everyone will be talking about.

Elsewhere in the cast, Guy Pearce plays Aldrich Killian, a renowned scientist  and old friend of Gwyneth Paltrow’s Pepper Potts (who gets to be much more than just Tony’s bit on the side here), who’s developed a cure for his own disabilities, while Rebecca Hall plays his botanist assistant (and former flame of Tony Stark). While Guy Pearce is as reliable as ever, the only real complaint of Iron Man 3 is that despite a fair amount of screen-time, Hall and – in particular – the enemy enforcers played by James Badge-Dale and Stephanie Szostak are largely just under-developed ciphers.

Shane Black’s direction is vibrant and assured, and his command over the big set-pieces is hugely impressive. The action is coherent and the spectacle is just that – spectacular! The script is equally confident, and it’s all so snappy that you could never hope to catch all the beats on a single viewing.

This is by far the funniest Marvel film so far, and it segues seamlessly between maturity (the genuine exploration of Tony Stark’s character) and the childish (Tony’s banter with the 11 year old boy he befriends reduces both to play-ground insults.) The script is bursting with life, and there are references to everything from cult-classic Christmas movies to Croydon! (One suspects we can think British co-writer Drew Pearce for that one.)

Like Avengers Assemble, Iron Man 3 is everything you could want from a Marvel superhero movie. It’s bright, exciting and funny, but isn’t afraid to add depth to proceedings, while there are a few surprises that will have your jaw dropping with glorious incredulity. Erasing the memory of Iron Man 2, Shane Black has guided Marvel’s biggest solo property emphatically back on course, and Marvel’s Phase II is off to a hell of a start.

Released in UK cinemas on Thursday 25 May 2013 by Marvel.

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