By Darren Waters BBC News Online entertainment staff

X-Men 2 is one of the big blockbusters of the summer and is expected to dominate the global box office.

The golden rule of any blockbuster sequel is to give the audience more of everything - and in this respect at least, X-Men 2 does not disappoint.

There are more mutants, more action scenes, more special effects and more storylines.

Wolverine returns with sharpened claws

But this sequel is not just bigger, brighter and brasher - it's also better than the original.

The films picks up in the immediate aftermath of the original and very little back story or pre-amble is given.

For those out of the loop: mutants with extraordinary powers have begun to appear on the planet but some human beings, fearful of this evolutionary leap, are trying to stamp them out.

In the first film, a group of vigilante mutants led by Sir Ian McKellen's Magneto want to confront the human threat head on, while more peaceable mutants, led by Patrick Stewart's Professor X and his X-Men, favour reasoning and education.

Unite

The two sides clash leading to Magneto's imprisonment in a plastic jail - where his mutant powers are rendered useless - and Hugh Jackman's loner Wolverine embarking on a quest to discover the truth of his past.

Cyclops: Blink and you will miss him

And so begins the sequel, but this time the threat from humanity is so great that the two mutant sides are forced to unite in order to survive.

Director Bryan Singer again brings a touch of visual flair and great energy and pace to the blockbuster and his hand remains steady throughout the big set pieces.

He is aided by excellent performers like Stewart and Sir Ian, who manage to give often ridiculous material a sense of gravitas - much as they did in Star Trek and Lord of the Rings.

The only downside is that in effort to be bigger and brasher, Singer struggles to keep all of his balls in the air at one time.

Shock death

The numerous minor characters, sub-plots and themes in the film all get tangled as the film picks up pace.

The movie is essentially an ensemble piece but not all of the characters are treated equally.

One lead character from the first film disappears from all but five minutes of the sequel, while a shock death at the end of the film feels contrived.

The necessity of keeping a sequel-friendly ending also contributes to a messy and unsatisfying conclusion.

But even though the film is at times patently absurd, Singer manages to keep the x-factor in X-Men 2.

There remains enough life in the franchise to ensure that X-Men 3, 4 and even 5 are distinct possibilities.

If nothing, the film is always cool enough to grab one's attention.

Whether it is as cool as soon-to-be-released The Matrix Reloaded - another bigger, brasher sequel - is uncertain.

But it will make for a fascinating box office battle.