“Avengers: Age of Ultron” has become a major box office success, but it was not an easy film for Joss Whedon to direct. The filmmaker revealed in an interview with Hero Complex that the sequel to 2012's “The Avengers” was the “hardest work” he has ever done. Though Joss believed that making “Avengers: Age of Ultron” was a “great idea,” he had his doubts.

“I wanted it to be better, if possible, than the first one -- not that the first one was the best movie ever made, but I wanted to do better, just be better at shooting. I had doubt that I don’t usually suffer from,” he said. Whedon added that he felt paralyzed due to indecision and the weight of the responsibility for the movie. However, he snapped out his “paralysis” and went on to make a successful film. 

Whedon reportedly wanted the sequel to be better than the original, so he devoted time to every element of the film, believing that a sequel should be made only if there is something new to tell the audience.

“Avengers: Age of Ultron” shows Tony Stark (Robert Downey Jr.) reviving a dormant peacekeeping program and devising Ultron, a creation that turns evil and wrecks havoc on humanity. The calamity brings the Avengers back together as they fight Ultron to save the world from his malicious deeds. The film also stars Chris Hemsworth, Mark Ruffalo, Chris Evans, Scarlett Johansson, Jeremy Renner, Don Cheadle, Aaron Taylor-Johnson, Elizabeth Olsen, Paul Bettany, Cobie Smulders, Anthony Mackie, Hayley Atwell, Idris Elba, Stellan Skarsgård, James Spader and Samuel L. Jackson.

The film has received positive reviews from critics and has grossed more than $881 million worldwide. It is the second most successful film of 2015 after “Furious 7.” Marvel will follow “Avengers: Age of Ultron” with “Captain America: Civil War” and later “Avengers: Infinity War Part 1” and “Avengers: Infinity War Part 2.” The shooting of  “Captain America: Civil War” has already begun and it will hit theaters in April 2016. The film has been set after the events of “Avengers: Age of Ultron” and will see the formation of two groups of Avengers.

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