It's a scary thought to realise that the Brett Ratner version of 'Hercules', starring ex-wrestler Dwayne Johnson aka the Rock, is likely to be the best of a busy year's worth of movies featuring the legendary character.

It doesn't descend to the depths that I hear were plumbed by Renny Harlin's 'The Legend of Hercules' with 'Twilight' star Kellan Lutz and there hasn't been a good Asylum cash-in yet, so 'Hercules Reborn', starring another wrestler, John Morrison, isn't likely to touch this one. Yet, while there's a good movie in the material, sourced from a graphic novel by Steve Moore called 'Hercules: The Thracian Wars', this isn't it.

It starts off well, displaying a narrative flair and a sense of humour, as we're reminded yet again about the legend of Hercules and try to forget yet again that popular culture ruthlessly mixes up their Greek mythology with their Roman. Here, as tends to be the case nowadays, Hercules is the son of Zeus, the king of the gods, and the mortal woman Alcmene, and Hera has tasked him with twelve labours before she'll let him be. He's completed eleven but still has to defeat the beast that haunts him, the three-headed Cerberus.

We soon discover that we're being told tall tales, along with a crew of pirates who are about to kill Hercules's nephew, Iolaus. His storytelling is the only thing keeping him alive until the man himself shows up to save him which, naturally, he soon does. This is fun stuff, action-oriented comedy with a flippant and light sense of humour. It reminds very much of the 'Hercules: The Legendary Journeys' TV show with Kevin Sorbo, even though Johnson looks both notably different to Sorbo and the Rock is an awkwardly strange sight with hair.

The action and comedy continues, but the meat beneath the bones is that suggestion that all the stories are just that, stories. We don't know who started them, but Iolaus is all about telling them as often as possible and with as much exaggeration as his audience will believe. The whole point is that their propagation helps build Hercules's image and thus boosts their collective trade as mercenaries. The fact that Hercules is a vast mass of rippling muscle who isn't fazed by odds of 40 to 1 helps too, but the stories are heard by more than get to see those muscles.

There are six companions all told, each joining Hercules during one of his prior adventures, and frequent namedropping at the outset helps us identify them. Atalanta is the Amazon warrior, Autolycus the thief, Amphiarus the seer and Tydeus the half-crazed warrior who was literally born on a battlefield. They're capably played by actors as strong as Ian McShane, who owns this film, and Rufus Sewell.

As this mercenary band heads off to Thrace to train up an army of farmhands to help defend the kingdom of Lord Cotys from the sorcerer Rhesus and his army of centaurs, we're holding out hope because the subtext of celebrity is an interesting concept for a Hercules movie. It isn't merely that Hercules can boost his own reputation through the tall tales of Iolaus, it's that others can do precisely the same thing and that reputations can come with a particularly heavy price.

Most of this story is driven by erroneous perception because legends are easier to believe than the truth, even when you're one of those legends. Midway through, we discover that Hercules is flawed himself. He doesn't remember killing his wife and kids but apparently that's what happened to drive him out of Athens. Since then he's been plagued by nightmares that threaten to do him real harm.

The middle third of the film is weak but agreeable enough as the depth gives way to a host of battle scenes, which are agreeably bloody even if they're annoyingly one-sided. The soaring views of the countrysides of Hungary and Croatia look great but pale compared to our memories of New Zealand from the Sorbo TV show. Amphiarus has a host of cool gadgets, like chariots with blades coming out of their wheels, leading this to have a 'Wild Wild East' undercurrent.

Of course, we can't fail to realise that there's something coming, something that Hercules hasn't figured out yet, and that's what leads us into the third act, which is where the whole film falls apart. Everything becomes a plot convenience until the subtext can be shoehorned into a nice little tagline for the film about the nature of heroism. The twists are like WWE twists, so relentlessly and unbelievably back and forth that I fully expected Hulk Hogan to win the final battle.

Johnson does a capable job as Hercules, playing to the audiences at home as much as the ones in the story. His portrayal fits the subtext because he looks the part and performs impressive enough feats to make the stories about him believable, without ever selling to us that he might just be the son of Zeus after all.

His cohorts are similarly capable with Ian McShane the clear standout as the seer who's right most of the time but can't quite figure out when he's going to die. I've seen McShane's work ever since his days on TV as 'Lovejoy' but this may be my favourite of all the parts he's played. It surely isn't the most substantial, but he clearly has a blast.

So now we've seen the Rock as Hercules and we're entertained but underwhelmed. Sadly we won't ever get to see Hercules as the Rock, because Ray Fernandez died in his sleep in 2004. Otherwise I might have preferred that movie.