Jack the Giant Slayer

You may think of fairytales as moralistic fables handed down and gradually sanitised through successive generations. But where you see collections by the Brothers Grimm or Perrault, Hollywood sees a cheap, robust, copyright-free resource with franchise potential. And so, arriving on the heels of the not-very-good Hansel and Gretel: Witch Hunters , the not-much-better Jack the Giant Slayer looms over a multiplex near you.

A large company of screenwriters and executives – seldom a good sign– have opted to keep farm boy Jack and the magic beans but not much more of the source material in this heavily pixelated $200 million adaptation. Instead, we’re treated to a larger, exciting mythology about giants who are banished – after a people-eating prologue – to live between the earth and the sky. The back-story is gripping; the finished product, alas, is a lot less sure-footed.

The trouble with Nicholas Hoult 's dreamy, blue-eyed Jack is that he seems to have no discernible traits beyond being blue-eyed and dreamy. If he's heroic, it's only because he's standing beside Eleanor Tomlinson 's drippy, useless princess. The secondary characters, at least, make for livelier company. King Lovejoy is the reigning monarch. Ewan McGregor has fun with the same plumy vowels he brought to Obi Wan Kenobi. Stanley Tucci and Eddie Marsan are, well, Stanley Tucci and Eddie Marsan.

These Great Acting Staples go some way to offset the damage left by an overreliance on the ghastly CG and a seeming desperation to put on an all-ages show. Jack the Giant Slayer can't quite decide if its Twilight puppy love or Princess Bride knowing, or "you know, for kids". The giants are sometimes scary, sometimes flatulent. The humour is sometimes winking, sometimes baseline scatological. The only constant is the film's tatty digital, an aesthetic that recalls last year's hermetic Mirror Mirror rather than the outdoorsy, consciously epic Snow White & the Huntsman .Be warned: scenes depicting rolling countryside may induce Green Lantern flashbacks

Giving the commanding giant a thick Northern Irish accent is a sweet touch – just like the Causeway, get it? – but it does, unfortunately, leave us watching noble Englishmen trying to kill misshapen Ulster folk for almost two hours. Ahem.