A complete delight, this is a fish-out-of-water comedy based not on age, but on the shifts in cultural cache that have occurred over the last ten years or so - with plenty of slapstick, swearing and high speed chases thrown in for good measure. The dialogue also does a nice line in pithy put-downs - if you can think of a better three-word description of Jonah Hill's appearance than "cherub-looking motherfucker", get thee to Hollywood.
The film's real revelation however, is Channing Tatum, who what with looking like a live-action Mr Incredible tends to get cast as military types, whether historical (The Eagle), tear-jerking (Dear John) or plain silly (G.I. Joe). Here, he's allowed to send up his looks and the presumption that someone who looks like that must be a himbo, and the result is a joy to watch; he's a nimble physical comic, but equally capable of selling the emotional highs and lows. Despite having the meatier character arc, Jonah Hill (who co-scripted the film with Scott Pilgrim's Michael Bacall) must work hard to keep the double act balanced.
The culture shock faced by these twenty-somethings heading back to high school to find eco-cool, internet-savvy, beautifully-dressed cliques of mature, politically correct and sexually liberated teenagers occupying the peak of the school's social pyramid is a thing of beauty. The film doesn't labour its point that things have changed since the days of jocks vs nerds, but this theme does help tease a sly contemporary relevance from that most-unpromising of starting points: a recycled eighties TV show.
Ultimately, what makes 21 Jump Street so refreshing is that it's relatively free from the dubious whiff of political incorrectness added purely for the sake of convincing idiots they're watching edgy, challenging "banter", which has marred a few comedies of recent years (see: The Hangover). 21 Jump Street proves you can be fresh, funny and filthy without punching down.