Silly gags, over-the-top performances and shameless mockery make 'Walk Hard: The Dewey Cox Story' a must-see.

This mockumentary biopic, from the makers of 'Superbad' and 'Knocked Up', tells the story of Dewey Cox - not your average country child. Stricken with tragedy, cast out by his father and not blessed with good looks, Dewey turns to his unique gift to set himself apart. He has a powerful voice, is a great music mimic and pens songs that seem to mesmerise people. And so the comedy begins in earnest.

Dewey's rocky journey along the road to fame, complete with marital difficulties, drug dependency and affairs, is played out in spectacular fashion, borrowing chapters from all the great music biopics, but predominantly the recent Johnny Cash movie 'Walk the Line'.

Many scenes will crack you up as you watch this but The Beatles meditation gags are probably the most memorable of the movie. With cameos from Justin Long, Jason Schwartzman, Paul Rudd and Jack Black as the famous four, this could only be priceless. References to Elvis Presley, Buddy Holly and The Supremes are also worthy of a few decent laughs throughout.

John C Reilly is fantastic in this thick-and-fast comedy fest. He's everything the leading man needs to be, milking every last gag that the script offers him and proving that he is not just an actor for the fringes but can more than hold his own as the central character.

'Walk Hard' is the kind of movie that makes for uncomfortable viewing, but in a good way. You'll squirm a lot, laugh - although feeling guiltier with every chuckle - and then wonder how such crude, in-your-face gags could be so funny - but they are, for the most part.

At certain times though, 'Walk Hard...' borders on the extreme, making you think that it is a little too fearless where causing offence is concerned, and perhaps could have been pulled back a bit when it tended to get wild and wacky for the sake of it. But this is a small issue in a big movie and is easily forgiven, and forgotten.

Linda McGee

Read an interview with 'Walk Hard' star John C Reilly here.