'War of the Worlds' meets 'Skins' on London movie set

On a grimy south London council estate, hoodie-clad youths gather weapons to protect their "endz". Baseball bats, samurai swords, knives and guns are brandished. "Let's get tooled up, blood." "I'm killin' them straight!" So far, so familiar for a British teen film on a modest budget. But Attack the Block is a little more complicated. For a start, the rival gang has come a bit further than the neighbouring estate.

In a mash-up of genres – War of the Worlds meets Skins – the film is an alien-invasion-teen-gang romp with a flick of Gremlins thrown in for good measure. Produced by the same team that produced the zombie comedy Shaun of the Dead, it features the acting talents of Nick Frost and is a directorial debut for Joe Cornish, best known as co-creator of The Adam and Joe Show.

"It's a film made for young people," Cornish said last week. "Not exclusively, but certainly it's talking about the stereotypes, the way young people are portrayed and trying to shatter them. I don't see a lot of British cinema addressing teenagers, and I thought there was a gap in the market to do it in a respectful, different, exciting and escapist way without being too miserable or sensationalist."

The film opens with its stereotypical council estate hoodies mugging a middle-class nurse at knife-point. The darkly comic heart of the film is revealed when they are distracted by a meteorite – complete with alien passenger – hitting a nearby car.

Cornish was inspired to write the script after he was himself mugged. "It's a reprehensible thing to do. But the kid that did it to me, I would not want to make that one poor choice he made a burden for him for the rest of his life."

His upbringing in south London and his fondness for 1980s monster movies such as ET, Gremlins, Critters and Predator added grit to the idea. "Even the vehicles, like the BMX speaks to me of ET. The pizza mobile scooter reminded me of a speeder bike in Return of the Jedi," he said. "The estates themselves – the walkways, corridors and balconies – felt to me like spaceships or Nakatomi plaza from Die Hard, or like The Poseidon Adventure; the Nostromo starship in Alien. It felt as if the tower blocks were like massive, clapped-out spaceships."

But the setting and the aliens – gorilla-like with neon blue teeth – are mere supports to the true stars of the film, the young actors, who last week described how they had enjoyed having an input into their characters' dialogue.

In researching the script, Cornish talked to hundreds of youth groups from Kennington, Camberwell and Bermondsey in south London. Much of the dialogue was refined and informed by input from the young cast, said the director. "A huge amount. We had a long rehearsal process with them. I wrote the final two drafts after we cast them."

The process appears to have paid off in making even unlikely material sound plausible: "That's a alien, bruv, believe it" is followed by a menacing "They went and landed in the wrong place, you get me?".

Even before its release, the film is being likened to Shaun of the Dead. "That's very flattering," Cornish said. "But it doesn't have as many gags as Shaun of the Dead. People shouldn't feel like this is a hood film, or a niche film. It's a fun, escapist, action adventure romp and it's not just about the kids."

Attack the Block goes on general release on 11 May

Gang that saved the world

Moses, 15

(John Boyega, 18, from Peckham, south London. A student at the Identity Drama School)

"Moses is the strong and silent type. He doesn't live with his parents but with his uncle who is never around. He's just a good kid, a little boy who becomes a hero."

Dennis, 16

(Franz Drameh, 18, from Hackney, north London. Trained at the Young Actors Theatre)

"My character is the sword- wielding hothead. He's the first to charge into a crazy situation without thinking. But he's Moses's right hand. If Moses says let's go, he will be the first to follow."

Biggz, 15

(Simon Howard, 18, from Elephant & Castle, south London. Attended workshops at Peckham Theatre)

"Biggz is the youngest. He's the energetic buzz of the group. He makes people laugh. He's got a lot of passion for his mother and loves her a lot."

Jermone, 16

(Leeon Jones, 17, from south-east London. Spotted during a summer project with Mayhem Theatre)

"He's like the brainy one, the mastermind. He likes to look at things differently and asks is there another way we could do this?"

Pest, 16

(Alex Esmail, 17, from Camden, north London. Spotted during drama class at Acland Burghley School, Tufnell Park)

"He's the crazy one of the group. He's about 16, smokes a lot of marijuana and he's a bit of a mental case. He comes out with a lot of one-liners, because he's under the influence a lot."

Andrew McCorkell