There are movies based on theme park rides (Mission to Mars, Pirates of the Caribbean, the coming Tomorrowland directed by Brad Bird and starring George Clooney), on toys (Transformers, GI Joe, Bratz), on board games (Battleship, Jumanji, Zathura) and dozens inspired by video games (from Super Mario Brothers through to the recent Need for Speed).
However, when I heard that Hollywood had made an animated feature out of Lego, the cherished Danish building blocks first sold in 1949, I thought some Warner Bros executive had sucked too much paint out of one of the pieces. What would they think up next? Ikea: The Revenge of the Flatpack.
Even Chris Pratt was cynical about the studio's motives when approached to lend his voice to the lead character. "I thought it was all about brand recognition, that they were probably doing the Q*bert movie at some studio and a Connect Four movie," Pratt says, referring to two popular games.
"If anyone's heard of it, they are going to make a movie about it. The Kleenex Movie - there's money to be made in that."
But Pratt and the rest of the world needn't have worried because The Lego Movie is one of the year's nicest surprises - a clever, funny, wickedly subversive family flick that has some very wise things to say about parenting, the dangers of conformity and the importance of the imagination.
It is about a bland, cowardly instruction- follower named Emmett (Pratt) who's mistaken for The Special One, a bold, brilliant hero who would prevent the scheming President Business (Will Ferrell) from destroying all the various Lego worlds that do not stick to his rigid, regimented building codes and use their own imaginations.
When Emmett reluctantly accepts his destiny, around him gather a rag-tag group of rebels, including a Gandalf-like sage (Morgan Freeman), a feisty rebel (Elizabeth Banks) and, weirdly, Batman (Will Arnett).
"While The Lego Movie is undoubtedly the single most product-centric film of all time, it is also just hip and irreverent enough to leave audiences feeling as though its makers managed to pull one over on the business guys," writes Peter Debruge in Variety, in one of many rave reviews that have helped make the movie one of the year's biggest box-office hits in the US.
"They've gotten away with something, upholding and expanding the Cult of Lego - the plot literally serves to cement the right and wrong way to play the product - while good-naturedly skewering the consumer culture at large."
Actually, if we'd taken a look at the names of the writing-directing team behind The Lego Movie, Phil Lord and Chris Miller, our fears that it would turn out to be horribly synthetic Hollywood product designed to distract toddlers and sell more toys would have been allayed.
Lord and Miller are two of the smarter, quirkier creatives working in the Hollywood mainstream, a pair of Dartmouth College graduates who put a pleasingly eccentric spin on Cloudy With A Chance of Meatballs 1 and 2, and 21 Jump Street.
"It could have been a giant commercial for toys but we all wanted to use Lego as a medium to tell a fun story. We tried to be as true to the medium as possible," Chris Miller told the website collider.com.
Indeed, the duo found their inspiration from the Lego lovers themselves, those who take the product seriously and who would not swallow a pair of Hollywood big shots swaggering in and trashing a world they cherish.
"Chris and I were inspired by the ingenuity and humour that comes out of the international Lego community," says Lord, referring to such outlets as Lego Cuusoo, the Lego Group's fan submission site for potential new products, ReBrick forums, where people can share their creations, and the growing number of short films that use Lego bricks and figurines.
Committed to upholding that principle, Lord and Miller knew from the start that this could be no standard animation - that they would make an entire feature film with Lego bricks and elements.
"We both thought 'Wouldn't it be amazing to make a big, fun action-packed Lego adventure that captures the feeling of being a kid putting these pieces together but on a truly epic scale'," Lord explains.
"The appeal of Lego bricks is how accessible they are as an art form so we wanted to make a film that felt like something anyone could do in their own basement . . . provided they had a gigantic basement and a few million bricks!"
To achieve the handmade aesthetic that defines Lego, the filmmakers set out to synthesise the photo-real quality of contemporary animation with the feel of traditional stop-motion. That is, to use the latest digital technology with a technique as old as cinema itself. Indeed, the physical limitations of Lego mini figures is their charm, so there was no question of altering that in adapting them to a big-screen adventure, with the characters moving and interacting as if being manipulated by an unseen hand.
Even in their expressions the mandate was not to stray from the standard mini-figure repertoire: flat painted eyes, brows and mouths.
"Everything audiences see - whether smoke or water, rock formations, fire or even explosions - is made of Lego pieces. We wanted to depict natural elements built out of bricks as they've never been seen before on the big screen," producer Dan Lin says.
The unique retro look of The Lego Movie was achieved by Animal Logic, the Australian animation and visual effects company that made its name with the global smash Happy Feet, which won them an Academy Award.
According to Animal Logic chief executive Zareh Nalbandian, all of the animation, and effectively more than 95 per cent of The Lego Movie, was made in Australia by Animal Logic (there is a small live-action component that makes for one of the most inspired moments you'll see in a movie this year).
"We developed technology that allowed us to make a really amazing action movie but using virtual Lego bricks and some real Lego bricks," he says. "That took a lot of technology development and took a lot of pushing the envelope."
Once production moved to Australia, more than 368 people worked on The Lego Movie on and off over almost three years.
Nalbandian says they developed a brick- based technology which allowed them to create super-realistic Lego bricks virtually in a computer and build the movie from there. All in all, 15 million Lego bricks were used in making the movie.
"We look for those opportunities," Nalbandian says. "We look for those challenges on every film, whether it's penguins with feathers . . . or its dinosaurs that are 40 feet tall or little mini (Lego figurines) that are 20 inches tall but look like they were really shot in your basement."
'While The Lego Movie is undoubtedly the single most product-centric film of all time, it is also just hip and irreverent enough to leave audiences feeling as though its makers managed to pull one over on the business guys.' Peter Debruge, in Variety