Downey Jr: 'Iron Man' is light and simple

Robert Downey Jr. has admitted that his superhero film Iron Man won't be as "complex" as the recent Batman Begins.

Speaking at the UK premiere of the movie, the actor admitted that he and director Jon Favreau wanted to take the character in a different direction from darker superhero films.

He said: "Jon and I are big fans of what [Christopher] Nolan was able to do with Christian Bale in revising the whole Batman franchise. They did this very dark and complex take on a superhero. We felt they did that about as good as can be done so we tried light and simple."

The 43-year-old, who plays billionaire industrialist Tony Stark in the film, added that playing such a physically demanding role took its toll.

"Considering I was 41 when I was cast and turned 42 while we were shooting, I felt like I was visiting my retirement by the way I felt in the mornings," he said.