In 2004, Canadian cartoonist Bryan Lee O’Malley published the first volume in his Scott Pilgrim comic book series. It tells the story of a 23-year-old slacker who has to fight the seven evil ex-boyfriends of his new flame, delivery girl Ramona Flowers.

Director Edgar Wright was given a copy after the 2004 premiere of his cult comedy, Shaun Of The Dead. He wanted to film it straight away, but there was one problem: The story wasn’t finished! "I just stalled until there were more books," he told the BBC.

Filming began in Canada in March 2009 and took six months – "twice as long as my previous film, Hot Fuzz," Wright says. The high-octane visual style is lifted straight from the comic books. "There’s a lot of work up on the screen," Wright notes.

Some sequences are almost shot-by-shot recreations of the comic. "The material was just really good," Wright says. The director reveals the books and the film "have slightly different endings" but "we stay very true to the spirit and the tone".

The film and comic both pay homage to video games. Scott's battles begin with a Street Fighter-style "versus screen". When he defeats an enemy, they explode into a Super Mario shower of coins, and his band is named Sex Bob-omb after a Mario baddie.

Wright says film studio Universal was "blown away" by the film's cartoonish visuals. He was not asked to make major changes because everything was "laid out completely" in advance. "They had the storyboards for the whole thing, so nothing was a surprise."

Jason Schwartzman and Michael Cera needed "a month of constant work" to film their fight scene. "You can't let your mind get distracted," Schwartzman notes. "If I forgot one of the moves because I was exhausted, I could really hurt him and vice versa."

Judging by their appearance at this press conference, the film foes became firm friends off-screen. "I’d love to have a painting of this moment," Cera says. His co-star adds: "If there are any artists watching, we’d love to get something embroidered."

Music features heavily in the story, with indie superstar Beck penning songs for Scott's band. Schwartzman likens the film to a musical. "There's a real pace to it, like there's a metronome going 'tick tock' and everything has to stay in time with that."

Scott Pilgrim only took $10m when it opened in the US, but Wright is unperturbed. "Spaced and Shaun Of The Dead had to percolate for a while before they found their audience," he notes. "And I’ve never had a film in the top five before, so I don't care!"