 These and other continuing fan activities eventually persuaded Universal Studios to produce a feature film , Serenity . ( The title of Serenity was chosen , according to Whedon , because Fox still owned the rights to the name ' Firefly ' ) . Numerous early screenings of rough film cuts were held for existing fans starting in May 2005 as an attempt to create a buzz to increase ticket sales when the final film cut was released widely on September 30 , 2005 . The film was not as commercially successful as fans had hoped , opening at number two and making only $ 40 million worldwide during its initial theatrical release . 
