Is this the worst movie ever made?

"The Citizen Kane of bad movies" (Entertainment Weekly); "a bad – shockingly bad – romantic tragedy" (Time Out New York); "prompts most of its viewers to ask for their money back – before even 30 minutes have passed" (Variety). Most film-makers have nightmares about reviews like these, but they've worked wonders for The Room, a movie whose transcendent awfulness has made it a cult phenomenon and an audience-participation fixture along the lines of The Rocky Horror Picture Show.

It's difficult to make any sort of movie, good or bad, but to make a movie that's so bad it's good you need vision, drive, luck and obsessive vanity. Fortuitously, The Room's writer/producer/director/star Tommy Wiseau appears to possess all of these qualities, combined with a total lack of acting talent.

A mix of Tennessee Williams, Ed Wood and R Kelly's Trapped In the Closet, The Room is a simple story of a guy whose fiancee is cheating on him with his best friend, but devastating plot points such as cancer, drugs and pregnancy are thrown in – then completely forgotten about. Characters disappear halfway through the film, the softcore sex scenes are excruciating, and the San Franscisco setting (it was actually shot in Los Angeles) is alluded to by amateurish back projection and repeated shots of the Golden Gate Bridge.

And elevating the whole affair to high-trash status is Wiseau himself, with his slurry Schwarzeneggerian accent and resemblance to a gym-pumped Christopher Walken in a wig. "It's like your favourite nightmare," says comedy writer and Room convert Robert Popper. "It's horrible to watch the whole time. You know how if you watch The Godfather, every scene is a masterpiece? It's the same with The Room: every scene is perfectly bad."

The Room first gained notoriety in Los Angeles, partly thanks to a billboard advertising it that stood over Sunset Boulevard for five years. The film's unique ineptitude began to attract rowdy repeat viewers, who would shout abuse ("Focus!"), lip-sync the worst lines ("You are tearing me apart, Lisa!") and hurl plastic spoons (the movie features a lot of spoons). Celebrity fans such as Twilight's Kristen Stewart and Superbad's Jonah Hill also helped spread the word.

Having held the UK premiere of The Room last Saturday, London's Prince Charles Cinema is starting monthly midnight screenings, and it is also playing at the Barbican's Bad Film night (23 September), with contributions from Popper and fellow comedy writers Peter Serafinowicz and Graham Linehan. Wiseau himself often turns up to screenings, and now claims The Room was intended as "a black comedy". He's thinking of turning it into a Broadway musical.