I should hate Crank. After all, it features hyperactive MTV-style direction, a ridiculous plot and bad acting by the ton. But instead I ended up enjoying it a great deal. It's a film that knows it's trash and just wants you to have a good time – plot and character are unimportant.

The reason why the film succeeds so triumphantly is because of the film's wicked sense of humour. The central conceit – that a man is poisoned and has to keep moving to stay alive – is a just a vehicle to bring about a group of preposterous situations, all of which had me grinning like a loon.

The scene that had me laughing hardest was when Chev (Jason Statham) chops a bad guy's hand off with a meat cleaver. Fair enough, that doesn't sound that funny in itself, but there's a genius bit where the guy, with a stump now for a hand, tries to punch Chev in the head. Chev moves and the guy's stump slams into the concrete floor with a meaty thud. Brilliant! And even better, Chev finally kills the guy by picking up his chopped off hand, which is still clutching a gun, and shoots him. Violence has never been so ingenious, or as funny.

Another inventive piece of violence occurs when Chev goes to pick up his girlfriend at her apartment. Little does she know that some bad guys are on the way to kill her, but without her even realising – the phone rings and then later the contents of her handbag get thrown to the floor – Chev takes them out. It's a wonderful bit of comedy, kind of like something Buster Keaton would have done if he'd been into guns. The timing is perfect. And there's also a great bit where an old woman's budgie gets blown away as Chev is wrestling with a guy over a silenced handgun. If that doesn't make you laugh you're dead inside.

You're also dead inside if you don't laugh at the idea of someone having to fuck to stay alive. Honestly, the public sex scene is a delight. Everything from the initial failure to get it up, the arse slapping and the triumphant moment when Chev takes his girlfriend from behind as everyone watches and as he cheers, 'I'm alive!' had me in stitches.

I also liked the scene where Chev gets a blow-job in the middle of a car chase. It's no less silly than all the other stupid scenes where characters get the horn in action films and have sex in inappropriate places, but the difference here is that it's done with a nod and a wink. You know it's silly and the filmmakers know it's silly, but the complicity allows you to laugh along with the film rather than at it. And with lines like 'Jesus, you're so big' thrown in as Chev gets blown and kills people at the same time, you can't help but admire the filmmaker's insane commitment to producing a film that perpetually stays in the realms of bad taste.

However, as funny as the chase scene is, there was a moment that made me cackle even harder. There's a bit where Chev, high on epinephrine, and clothed in a hospital gown, runs through town. He stumbles upon a news report concerning his antics, which is watched by a growing crowd. At first no one notices him, but then a man looks over, and then looks down, and because of the drugs Chev is on he's confronted by the fact that he has a massive boner. The glower that Statham gives the guy is perfect.

Yet another scene that had me laughing my arse off: Chev is in a taxi and is slowly beginning to pass out. To wake himself up he gets the Arab cab driver to turn the radio up. Chev then starts head-banging to 'Achy-breaky heart'. And then after robbing a store and filling a bag full of energy drinks, he hurls the cabbie to the floor and shouts, 'Al-Qaeda'. Suddenly a bunch of old fogies leap on the poor guy and begin breaking limbs. Honestly, people who call this a dumb piece of crap are deaf and blind. This is one of the most inventive, witty and gleeful action films I've seen in years.

But unfortunately most people seem to be blinded by the violence, sex and bad taste jokes. Plus there are numerous references to computer games – it owes a large debt to Grand Theft Auto, what with its frequent top down views of the city, cheesy graphics and characters who can survive masses of punishment and keep going. Therefore it's been tagged as empty-headed drivel. But instead it's a playful jab at action movie clichés and conceits whilst also acknowledging how fun they are. It's like Speed but without the po-faced attempts to build character and supply emotion. This film, what with its 'medicinal' coke snorting, public sex and gratuitous violence, is only interested in the gut. It wants to make you laugh and wants you to get caught up in the excitement. And for me it worked superbly. After all, any film that has a scene where a man shocks himself with a defibrillator to get out of a shootout and to keep his achy-breaky heart going, has got to have something going for it, hasn't it?