Robert Zemeckis was originally hired as director, and spent a year working on it in development. He was at the time directing "Romancing the Stone", another film for the same studio, 20th Century Fox. Fox executives previewed "Romancing the Stone" before its release in 1984 and hated it. That, in addition to his two previous directorial efforts, "I Wanna Hold Your Hand" and "Used Cars", both being commercial failures (though critically acclaimed) led the studio to fire Zemeckis as director of "Cocoon". He was replaced with Ron Howard. ("Romancing the Stone" turned out to be a huge commercial success and gave Zemeckis the clout to do "Back to the Future", which had previously been turned down by every major studio.)