Harrison Ford, Daniel Craig Talk About Slinging Guns, Slaying Space Invaders in 'Cowboys and Aliens'

"There's a sort of simple ethic that the western man lived. It really was self-reliance," Ford said. "It was simple rules: finish what you start, do the best job you can, be a good worker. They were work ethic rules, really. It's nice to do a film that has...a simplicity and straightforwardness, something really sort of black and white."

"It's a classic American form," said Favreau. "And it's opera. It allows you to tell these sweeping stories and it allows you to really focus in on character arcs and moral struggles that characters are having."

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Favreau said that he wrote a Western following the success of his breakthrough 1996 film, "Swingers," and had been trying to get one the big screen ever since. Though "Cowboys and Aliens" involves intergalactic war, Favreau said he wanted to "maintain the structure of a Western and the sensibility of a Western" for his debut into the genre.

"The West is big and people feel small in this type of backdrop and, I think, accentuating the smallness of people is what makes the struggles, the character struggles, in a Western, really resonate," he said. "The aliens give ["Cowboys and Aliens"] an opportunity to open it up and make it something that's a little bit original, a little different, but we never wanted to give up that ground that was the Western tradition."