Serenity joins a handful of films (1979's Star Trek: The Motion Picture, 1992's Twin Peaks: Fire Walk With Me) with the somewhat dubious distinction of transferring short-lived TV series to the big screen. Like Twin Peaks and the original Star Trek, Firefly, the show for which Serenity serves as an extension, has a rabid cult fan base, fans who helped the DVD of the show's single season (only 11 episodes of which aired on Fox in 2002) sell more than 200,000 copies and regularly dress up as the show's characters at conventions and events.
Also as with Star Trek and Twin Peaks, Serenity has a serious hurdle to overcome in terms of appealing to non-fans. Creator Whedon, who writes and directs the film, has said recently that he writes "from a fan-boy place," and Serenity is first and foremost a movie that will fulfill the hopes and dreams of each and every Firefly fan. It takes one of the show's central subplots and brings it front and center, following outlaw spaceship captain Mal Reynolds (Fillion) as he and his crew attempt to shield teenager River Tam (Glau) from the clutches of the evil Alliance.
Telling River's story is satisfying for ardent fans because it resolves one of the show's biggest mysteries, and it's good for newcomers because it feels important, and is full of as much action as befits a big-screen, space-faring adventure. Whedon made the film on a budget about half as large as that of your typical high-profile sci-fi flick, and he does an excellent job of stretching his resources and making his universe both impressive and convincing.
At the same time, Serenity suffers from the same problem that plagues most of the Star Trek films: It feels like an extended TV episode. It's a very good episode, but it's still dependent on what's come before, and ends with a setup for future adventures. Whedon takes positive steps toward expanding the scope beyond the small screen, including introducing a chilling new antagonist played by Chiwetel Ejiofor (who, between this movie and Four Brothers, is showing a real knack for villainy) and relegating a couple of the show's unwieldy nine main characters to small supporting roles.
Whether Serenity will appeal to a broad audience is hard to say, but as far as this year's movies wrapping up sci-fi franchises with obsessive fans go, it's a damn sight better than that Sith film.