Joss Whedon thought he was going to ''die'' on set of 'Avengers: Age of Ultron'.

The 50-year-old screenwriter and director has admitted he found it ''tough'' focusing on each of the 11 main characters whilst filming the upcoming instalment of the movie series.

He said: ''It is tough. There's basically 11 main characters in this movie, which is quite frankly too much. I may die.

''Thor's probably the hardest to write at any point because his adventures tend towards the legendary and you can only have so much of that before people start to go: 'Wait a minute, whaaaat?'

''But the fun of the thing is taking Hawkeye and the people who don't have their own franchises - Banner, Natasha, the new guys - and delving into their lives.''

And Joss insists he isn't worried about what fans think about the flick and is, instead, focused on what he wants.

He added to The Guardian newspaper's Guide magazine: ''I don't really think about the fans. I think about what I want because I'm the guy who's taking the comic book he read as a kid and turning it into a movie that I want to see as much as I want people to see it.

''[Marvel Studios president] Kevin Feige and I are fanboys, straight up. But we also know that if you just spend your time catering to the fans you make something that is hermetically sealed. The first question we always ask is: 'What is the way in for someone who has never seen a superhero movie?' You need to be thinking about everybody all the time.''