According to wikipedia, there are only four full-length films shot entirely in Esperanto. One of these four is the 1966 black-and-white horror film Incubus, starring William Shatner.
The film had an LA premiere, but then, partly because of the Esperanto dialogue, it never found a distributor except in France and fell into obscurity. For years it was believed that all copies of the film had disappeared, until the 1990s when a copy was found in France.
In the Nov 7, 1977 issue of New York magazine, Bill Flanagan reviewed Close Encounters of the Third Kind. He hated it, and he was certain that everyone else was going to hate it too, predicting it would be "a colossal flop" and almost gleefully forecasting financial disaster for Columbia Pictures as a result, since they had bet heavily on the movie's success. He dismissed the fact that everyone else in the pre-screening he attended seemed to like it, noting, "When you give people free tickets to a movie, most of them are nice enough not to bitch."
"Upon its release, Close Encounters became a box office success, grossing $116.39 million in North America and $171.7 million in foreign countries, totaling $288 million. It became Columbia Pictures' most successful film at that time... Ray Bradbury declared it the greatest science fiction film ever made. Based on 46 reviews collected by Rotten Tomatoes, 96% ("Certified Fresh") of the reviewers have enjoyed the film and the site's consensus states "Close Encounters' most iconic bits (the theme, the mashed-potato sculpture, etc.) have been so thoroughly absorbed into the culture that it's easy to forget that its treatment of aliens as peaceful beings rather than warmongering monsters was somewhat groundbreaking in 1977."