'21 Jump Street' review:

"We're reviving a cancelled undercover program from the 80's" says a police captain near the start of '21 Jump Street' - a self-aware comic re-imagining of the 1980s cop show that most famously launched Johnny Depp as a heartthrob. In this version it's left to a mismatched buddy pairing - of a sporty airhead (Channing Tatum) and a brainy dweeb (Jonah Hill) - to track down teenage drug dealers, as hapless rookie cops sent to infiltrate a high school posing as students. Yet they both have unfinished business left over from their own school days which ensures they are soon more focused on making a second go of high school life, with Hill unexpectedly befriending the cool set, whilst Tatum becomes the unlikely champion of the science nerds.

As former high school antagonists turned best friends it's inevitable when they begin to turn on each other during the second act, yet - in a refreshing twist on a tired formula - it's Hill who comes to marginalise the strapping jock, rather than simply seeing the two revert into their old roles. Sometimes the comedy leans too far towards knowingly shocking excess, whilst the plot and "bad-ass" aspirations of our heroes threaten to veer uncomfortably towards a right-wing fantasy, yet its heart seems to be in the right place thanks to the film's tendency to make everything as broad and lovably ridiculous as possible.

Hill and Tatum make for a funny and charismatic double-act, whilst the film's many in-jokes at the expense of formula cop series (like the original) and tropes of the high school comedy allow for a disarming bluntness about the stupidity of its own premise.There are perhaps too many action scenes, with car chases and gun battles now a staple of the Hollywood "dude comedy", and these do drag the film down for long spells. But when it's funny it's funny enough that you more or less forget all the bits you didn't like... and it's funny about 50% of the time.

Especially winning are the drug taking scenes, which seem fresh despite the fact drug trip humour has been done to death over the years: staged imaginatively and going to some fairly bizarre places. This married to the terrific interplay between the leads, deft physical comedy, and some unexpectedly great meta-humour, ensured I laughed long into the credits - possibly for the first time since the last film from directors Phil Lord and Chris Miller (2009's criminally overlooked Sony animation 'Cloudy With a Chance of Meatballs'). There's also a very clever cameo that's almost of 'Zombieland' proportions - and which you certainly won't want spoiled.

'21 Jump Street' is out now in the UK, rated '15' by the BBFC.