(MA15+) ****

Director: Matthew Vaughn.

Cast: Aaron Johnson, Mark Strong, Chloe Moretz, Nicolas Cage, Christopher Mintz-Plasse.

AS the superhero genre continues to thrive, so too does the off-shoot of films about superhero wannabes.

Following in the wonderfully demented footsteps of the unfairly ignored Defendor comes the equally excellent Kick-Ass, another tale of misguided vigilantes daring to live their dreams of saving the day in a cape and a cowl and getting in way over their heads.

Here it's Dave Lizewski (Johnson), a picked-on nerd and comic book fan, who decides it's time to make a difference and stand-up to the muggers and bad guys.

Unfortunately, his first foray into superheroing doesn't go to plan, but has unexpected side effects which draw him into the world of other caped crusaders, namely Big Daddy (Cage) and his foul-mouthed 11-year-old killing-machine-of-a-daughter, Hit Girl (Moretz). And as Dave's alter-ego Kick-Ass finds increasing fame, he also finds himself gaining unwanted attention from crime boss Frank D'Amico.

The film doesn't waste a second thanks to a lean and mean script that bounces from a concise-yet-unrushed first act through to a thrilling action-filled climax, barely stopping to catch breath along the way. Even the back story of Big Daddy and Hit Girl is fleshed out effectively in seconds, thanks to an in-film comic book - just one of the neat tricks Vaughn uses to keep things moving.

Every character is a winner, particularly Cage's Adam West-channelling turn as Big Daddy to Moretz's "c-bomb"-dropping anti-heroine, while Johnson ensures Kick-Ass retains enough heart and dignity despite being the butt of many of the film's gags.

The humour certainly pushes the boundaries, as much of it comes from dark places, but, believe it or not, it's hard not to laugh when an 11-year-old massacres a room full of baddies to the tune of The Banana Splits Theme.

Watching a kid spit profanities in between hacking limbs is not going to appeal to everyone (although, strangely, family groups had more problem with the cursing than the carnage), but then again comic-book movies aren't everyone's cup of tea. It's a shame really, because this is a fun, energetic film about taking part in society rather than just being a voyeur, with a neat age-old revenge tale tacked on.

Where Kick-Ass falls down is in how far you're willing to suspend your disbelief - the romantic subplot, the fantastically over-the-top finale, and even Hit Girl herself will be a stretch for some who want to embrace the "real-world superhero" approach of the movie.

But whatever faults it has are minor - Kick-Ass kicks arse (sorry, I had to).