Shepard will play an astronaut in the movie, about a board game that blasts a house and its occupants into space. "I'll be the only adult in it besides Tim Robbins," Shepard said in an interview.
Shepard added that he landed the role because of his ability to improvise in the audition. "Jon Favreau ... loves improv, so he'll read with you and just throw you curve balls and see what you do with it," he said.
Favreau plans to take advantage of improv when working with the film's cast of children, Shepard said. "I think [a kids' movie] is almost the best opportunity [for improv], because you have these kids who are going to be playing it by the book," he said. "The more you can screw with them, [the more you can] get something organic and real out of them."
The film is slated to go into production this summer.