Iron Man 2 gives things a damn good go nonetheless...

The film kicks off at quite a tempered pace. Freed of the need to set up the character of Tony Stark and, as a consequence, Iron Man, it opens up the beginning of Iron Man 2 for director Jon Favreau to spend some time with his characters.

It's time quite well spent too: the first act of Iron Man 2 manages to introduce Mickey Rourke as Ivan Vanko and set him quickly on the path to becoming Whiplash, while it also begins to examine and nibble at the character that Tony Stark has become. Significantly, it digs into Stark's background and the relationship with his father, explaining some of the vulnerabilities in the character that the film subsequently explores.

As we join the film though, Stark is on top of the world. He's boasting that he's privatized world peace, while resisting attempts by the government – led by the brilliant, scene-stealing Garry Shandling as Senator Stern - to procure the Iron Man suit for itself as a weapon.

The moment arrives with the film's finest action sequence, the one that's been heavily pushed in the trailers. Rourke's Whiplash, driven by a hatred of the Starks passed down by his own father, makes his entrance in a grand racing scene in Monaco, and it's one hell of a way to say hello.

Rourke is clearly having a ball here, putting across a very still villain at times, whose actions look simply spectacular on the big screen. He's not a perfect movie foe: his mumblings are often hard to hear, and Whiplash is kept locked away for too much of the film's running time. But when he's unleashed, he's a sight to behold.

Here's where Favreau deserves immense credit, too. For he directs here an action sequence that you can both see and appreciate, freed of the desire for over-fussy cuts and too much use of the cam. Instead, he fills the screen with a scale you'd expect and demand from a massive summer blockbuster, and Whiplash's prowling around the track at Monaco is an outstanding piece of controlled action cinema. By contrast, the third act action that he melds together can't measure up to the same standard: it's still exciting, but there's little sense of the threat about it that permeates Whiplash's big entrance.

Worthy of note too is Sam Rockwell's turn as Stark's rival, Justin Hammer. While Tony Stark is reviving his father's Stark Expo project, Hammer is keen to ingratiate himself with the defense department to snap up some of their business. It doesn't take much to put Hammer and Stark at loggerheads, and nor does it take much selling that Hammer quickly becomes so interested in the carnage that Whiplash brings down.

All the while, Rockwell sells us a character that's a little uneasy, once or twice a little over the top, but pretty much always compelling. Arguably he's too much of a focal point for the ongoing story though, which is a problem for a film with so much to cram in.

Gwyneth Paltrow as Pepper Potts (in a beefier role than first time round), and James 'Rhodey' Rhodes, now played perfectly well by Don Cheadle.

It's hard to knock a film for wanting to flesh out side characters as well as developing the main faces, but there are moments where you can't help thinking this is a luxury that Iron Man 2 can't always afford. Because on top of all of this, it also has to squeeze in the introduction of Scarlett Johansson as Natalie Rushman and deal with her character's progression, too. And there's the small matter of a meatier, more pivotal role for Samuel L Jackson's Nick Fury as well. It's as if an admittedly-intriguing trailer for 2012's The Avengers movie has been wedged into the ingredients of a movie that already has too much in the mix.

Favreau and Theroux do, to their credit, get through a lot of storytelling in this part of the film, but the mid-story still slows things noticeably, before things are lifted again for the final act.

And, to be fair, Iron Man 2 does catch fire again. It packages in an exciting final third, which at times has you sitting back and simply appreciating the joys of a big, expensive, well-made blockbuster movie. It's hard too to sniff at Robert Downey Jr, who once more turns in fine work in the leading role.

Yet there's no getting away from it: Iron Man 2 is a film that can't quite recapture the magic of the first. You can't fault the fact that it tries: it throws as much as it can at you, admittedly stretching elements a little too thinly, but it's doggedly determined to give you your money's worth. There's little doubt that you get it, too.

You also get confirmation that Jon Favreau is a director who can genuinely handle action and special effects with real skill (as was, of course, originally proved in the brilliant, under-appreciated Zathura).

What you don't get however, which may just have been a little unrealistic to expect, is perhaps what you most wanted: a comic book movie that can be mentioned in the same breath as The Dark Knight, Spider-Man 2 or X2. Instead, by generous compensation, you do get a fun two hours, thanks to an ambitious movie that feels top to bottom like it was made by people who seem to love films such as these as much as you and I.

It might not be quite the Iron Man sequel that you were hoping for, but it's still a fine way to kick off the summer blockbuster season, and a happily entertaining night out at the movies.