Michael Sheen admits that he felt as if he were carrying the weight of the cyber world on his shoulders when he signed on to star in "Tron: Legacy." But the acclaimed actor, who counts the original "Tron" one of the films that greatly influenced his life, also says he also wouldn't have had it any other way.

"My grief was to bring a whole new energy to the film -- to be larger than life and to be a showman. It's always thrilling to attempt that sort of thing, and slightly daunting to deliver the goods," Sheen cheerfully said in a recent @ The Movies interview. "But once I started getting into the character -- who I think is a cross between a 1970s rock star and an emcee from 'Cabaret' -- it all started to come into focus more for me."

In "Tron: Legacy," opening in theaters and on IMAX screens Friday, Sheen plays Castor, the shady owner of the End of the Line club, a famous watering hole atop the tallest tower overlooking the Grid in the Tron world. He may or may not be of help to Sam Flynn (Garrett Hedlund), who has been transported from the real world into the Grid in an attempt to free his father, Kevin Flynn (Jeff Bridges), who has been held captive there for 20 years.

Sheen said he loves the complexity of Castor -- a sophisticated computer program who also functions as a raucous comedian and entertainer at the club.

"Castor runs the nightclub, performs in it and has Daft Punk as his house band," Sheen said. "But he also has a smokescreen personality. He shape-shifts and plays with identities and personas and reinvents himself."

There's no mistaking that Castor looks like David Bowie in the guise of his '70s rock hero Ziggy Stardust. But there's much more to the character than his looks.

"Castor is like a walking jukebox of pop culture that can roll out all kinds of references -- a little bit of 'Casablanca,' a little bit of Mae West and a little bit of Frank N. Furter from 'The Rocky Horror Picture Show,'" Sheen said. "So when I put all those things together, I started to think of Bowie and him creating Ziggy, Aladdin Sane and the Thin White Duke, and all those sorts of personas and pop cultural references he's played with. It helped me see who character was and knew it might make good reference points for the audience."

While his Castor's look and feel is rooted in the '70s, Sheen credits his overall performance to the 1982 event known as "Tron," which he first saw in the U.K. as a 12-year-old.

"My uncle took me and I didn't know anything about it. It was just something to do on a Saturday on a rainy afternoon in South Wales," Sheen recalled. "Then I came out an hour and a half later and my whole world had changed. If someone had been able to come up to me then -- a time traveler -- and said, 'In 27 years, you'll be in the next version of this film,' it would have been incredible. It was a huge influence on me."

Sheen, who's made his mark with such films as "Underworld," "The Queen" and "Frost/Nixon," said the original "Tron" not only made him a lifelong fan of the science fiction genre, it became "a touchstone about the power of cinema" overall.

"When the lights go down in a movie theater, it just totally transports you -- and when you walk back out into the real world, it's got a different kind of light to it because of what you've just seen," Sheen added. "I've never forgotten that.'Tron' was my first real experience of being changed like that. So to be able to be in this 'Tron' film is -- like that Woody Allen film 'The Purple Rose of Cairo' where you sort of go into the screen for part of the movie you are watching -- is amazing."

Because of his dedication to "Tron" Sheen said that he didn't find it unusual being asked to play a computer program in "Tron: Legacy." Sure, Castor is a character, essentially, but a character that is a program -- a type of role that doesn't come along every day for an actor.

"When I think about how I felt after seeing the original film when I was 12, I found it very unsettling," Sheen mused. "It may even have been the first film that I saw at that age, where I actively enjoyed feeling unsettled and disturbed. There was kind of a darkness to 'Tron' that was different from the 'Star Wars' films, except maybe 'The Empire Strikes Back' had a bit more of than the others."

Sheen said that he found Jeff Bridges' and Bruce Boxleitner's characters (Flynn and Tron) to be "a bit unsettling" when they were in the "Tron" world, so he hopes audiences view him in the same vein.

"The original 'Tron' world had this sepia Fritz Lang 'Metropolis' feel to it and I really liked that. So, for me to have the opportunity to play the character in this film is really unsettling and disturbing," Sheen said. "It went right to the heart of how I felt about the original 'Tron' film."