By Stephen James-Yeoman BBC News

Bollywood star Hrithik Roshan plays against type in the film

Bollywood's successes have been made on the magic of the musical romance.

But it is about to go where it has never gone before - into the realms of science fiction.

Koi Mil Gaya, or Found Someone, directed by Rakesh Roshan and starring his son Hrithik Roshan, is the first science-fiction film to be made in Hindi.

Complete with whizzing spacecraft and friendly aliens, the release of the film is set to make cinema history.

But director Roshan accepted the film was something of a risk.

Blockbuster effects

"This is the time to make a film and move ahead rather than make regular formula films," he said.

The team behind the effects in such blockbuster films as Independence Day, Godzilla and Spy Kids worked on the movie.

They had close to a third of the film's budget to create the animatronic alien.

Hrithik Roshan is more used to playing heart-throbs, but here he plays an 11-year-old boy, Rohit Mehra, trapped in a man's body. Mehra befriends the alien.

It is a departure from the lead roles he is used to, but one he has still been happy to make.

"I just basically looked at my childhood," he said. "I looked very deep inside myself and somewhere found a child... in a way it's an extension of my own childhood."

The film is one of a clutch of movies hoping to reverse the falling fortunes of the Indian film industry, which has suffered a disappointing year.