Speaking at a press launch in central London, he said The Simpsons Movie was “a tribute to the art of hand-drawn animation, which is basically disappearing”.
“All the animated movies these days are computer generated,” he said, adding that his film had been created in “the old-fashioned, clumsy, ‘erase it if you don’t do it right’ way”.
“It’s not a CGI movie with a thousand perfect penguins dancing in unison,” he continued – a reference to Happy Feet, the winner of this year’s Oscar for best animated feature.
Journalists at Wednesday’s preview were treated to a 10-minute excerpt showing many familiar characters.
Scenes included naughty adolescent Bart Simpson skateboarding through the fictional town of Springfield naked and his intellectual sibling Lisa meeting a potential new boyfriend.
Another sequence depicted US rock band Green Day being booed off stage for expressing green concerns – a suggestion the film will have a topical environmental theme.
Groening, who first conceived The Simpsons in 1985, said the thinking behind the film was to include “everything we couldn’t show on television”.
Matt Groening said the film would celebrate hand-drawn animation
“We hope it makes a little money too,” joked executive producer Al Jean.
The idea for a Simpsons film has been percolating since 1992, said Groening, but only came to fruition recently.
“Finally we decided that, as we were coming up to our 20th year and 400th episode, we should have a movie out,” he said.
According to Jean, however, it was not something into which they entered lightly.
“We couldn’t have felt more pressure, just because of the enormous love people have for the show around the world.”
That said, Jean is keen to point out one does not have to have watched the programme to appreciate the movie.
“Our ambition was if you’ve never heard of the Simpsons you can enjoy the film,” he said.
“It was important to us that it be viewed as a separate entity.”
Any suggestion that the belated film represents a winding down of the Simpsons franchise was hotly denied.
An extensive range of merchandise has already been produced
“Emphatically no,” said Jean, adding that he hoped the film would “help the franchise and bring more people in”.
Given the show has been running since 1987, it is unlikely there is anyone left who has not encountered America’s favourite nuclear family.
And with a goody-bag of merchandise awaiting journalists as they arrived for Wednesday’s event – including watches, drinking straws and even a stress relief aid shaped like a donut – the film is clearly viewed as a major summer cash cow.
Would Groening and Jean like their inevitable box-office success to be followed by awards recognition? Perhaps, though for now they are happy to trot out the usual cliches.
“I’ve thought about it,” shrugs the latter. “But there are many fine animated movies this year.”
“It’d just be an honour to be nominated!” adds Groening with his tongue firmly in cheek.
The Simpsons Movie is out in the UK on 27 July.