There's no other way to say this, but the Iron Man sequel is not great. Granted, it's nowhere near as awful as hyperventilating early slammings like this suggested, but a disappointment nonetheless.
Especially when compared to what a breath of fresh air the first was: a wise-cracking comic-book flick that was actually funny, and had a lead actor in Robert Downey Jr. who wasn't a fretting goody-goody, but a wild child who saved the day and told everyone about it (compare and contrast to the blank canvases of Tobey Maguire and Brandon Routh; and as good at Christopher Nolan's rebooted Batman has been, the growling Christian Bale is hardly the reason).
As we point out in our review, there are several reasons why Iron Man 2 doesn't live up to the promise - a saggy middle section where Iron Man basically sits around eating doughnuts chief among them - but then, comic-book sequels are tough things to master.
They should be the easy ones - you've got the first film out of the way, the one where you put in how they were bitten by a spider, or came from Krypton, or decided to suit up (otherwise known as an origin story to the fan-boys). Now you can let lose. You can wheel in the more exciting enemies. You can give your hero some angst. You can have fun.
Or not, as the case may be. So why do some comic-book sequels hit the button while others lose the plot? Here's NME's modest list of dos and don'ts. Feel free to disagree with them all - and then add your own.
DON'T... try to cram in too many characters
Most notably seen in the awful Spider-Man 3, where so many super-villians coalesced in the finale it felt like a WWF Royal Rumble, and the only thing you could be sure about was the CGI was expensive. This is a natural desire in comic-book films - during the course of a comic-book series, many villains will have been created, and studio's logic is the more they cram in, the more fans they'll have wanting to see it. The result, however, is often a muddled overlong mess where none of the stories or villains seem to matter, because none have been on the screen long enough.
DO... try and keep the same director
Granted, sometimes a franchise does need a kick up the backside, so perhaps this should contain a caveat: "if it's going well". Witness Tim Burton's wonderful first two Batman films - which envisaged the Batman world as a gothic marvel. After he left, the series resorted to hysterical comic-book camp and catch-phrases a-go-go. Everyone remember Arnold Schwarzenegger's "Ice to see you!" line in Batman & Robin? It feels like a Simpsons parody quote, doesn't it? Sadly, it was real. As were the bat nipples.
DON'T... base the film around a star name
There are many comic-book sequels this has ruined, where big name actors are essentially wheeled in to play themselves - Jim Carrey as the Riddler in Batman Forever being a prime example. But when it really went wrong was Superman 3. A battle behind the scenes between original director Richard Donner and the more jokey Richard Lester on Superman 2 (Lester won) set the stage for a crunching gear change on the third film, which essentially became a star vehicle for Richard Pryor, with Superman playing the straight man. It didn't work.
DO... continue storylines, not just cram in new ones
No better shown that with the acclaimed X-Men 2. Director Bryan Singer had got the origin story out of the way with the first, and planted seeds that could then really flourish in the follow-up. Not only did we get more action (a sequel must-have, obviously), but the themes - of prejudice and alienation - were explored in greater depth.
DON'T... get too contemporary
Film-makers need to remember that, in many respects, comic book films need to be timeless. So just because you're on the third film of the series, it doesn't mean it's time for a more modern "update" of the bad guys. Leave that to Bond.
There's no worse example of this than in the case of Superman IV: The Quest for Peace, which plunged itself headfirst into the nuclear arms race by creating a new character - Nuclear Man, who's spawned in the sun from a lock of Superman's hair (rigggggght), and flies from the flames complete with a cape and costume that says N on the front (I'm sorry - you were born with that?).
It ended with Superman finding a net big enough to fit in all the planet's nuclear weapons (stay with me), slinging them into the sun, and finding time to lecture the UN about the dangers of nuclear weapons. No, Superman, just no.