Directed by Shawn Levy starring Frankie Muniz, Paul Giamatti and Amanda Bynes.

As the star of TV's 'Malcolm in the Middle', Frankie Muniz has consistently put himself on the right side of the interesting/annoying child actor debate. And once you don't make the audience nauseous, the next jump is to cinema. But as Muniz proves in 'Big Fat Liar', the gap between small and big screens is a lot wider than people think.

Colourful but compulsive liar Jason Shepherd (Muniz) invents a colossal spoof to explain why he didn't complete his school English paper. But he's rumbled and dispatched home with a warning: come up with an essay in three hours or spend the summer with the school throwbacks in grind classes. So Jason fires off 'Big Fat Liar' and whizzes off to get his masterpiece to the teacher before the deadline.

But, in a tragic case of life imitating spoof, Jason is knocked off his bike by a limo containing Hollywood producer Marty Wolff (Giamatti), who then nicks the youngster's essay and later uses it as the plot for his next mega-budget outing. Naturally, no-one believes Master Shepherd's pleas of injustice and facing three months with apes in a classroom, he decides to hightail it to LA with buddy Kayleigh (Bynes) to confront Wolff and make him confess to Jason's parents that he swiped the story.

Muniz and Bynes make a nice double act but the script for 'Big Fat Liar' doesn't let them run amok as often as it should. There's one glorious 15-minute passage where they systematically set out to destroy Giamatti's life but the rest of the time 'Big Fat Liar' looks like a so-so TV movie that kept getting zeros put on its budget without the gags being added in equal measure. It's simply not subversive enough for the industry it's meant to send up, with a finale that's more Hardy Boys than Farrelly Brothers.

Muniz attacks every scene with zeal but he's hampered continually by the fact that Levy seems unsure whether he's pitching the film at the teen or single figures end of the kids' market. He's also unsure of just what do to with his cast: Lee Majors makes a ridiculously brief cameo as an ageing movie stuntman while the relationship between the two teenage tearaways seems to fizzle out in the second half of the film completely.

Younger viewers will get a laugh out of 'Big Fat Liar' but they'll forget about it the day after and go straight back to 'Malcolm in the Middle.'

Harry Guerin