Iron Man is an American science fiction superhero movie based on the Marvel Comics character Iron Man. It is the first movie in the Marvel Cinematic Universe (MCU). It was released in different countries on dates between April 30, 2008 and May 2, 2008. The movie follows a billionaire industrialist (Robert Downey Jr.) having a heart transplant. The movie was positively welcomed from both audience and film critics. It was the number one movie in the United States in the opening weekend.