I would instead say that the movie fell (a very little bit) victim to the de-SciFication disease where in the structural heart of sci-fi -- social thought-experiment allowed to run without conventional limitations -- wastes away upon repetition/going large-format. Normally, this experimental core gets replaced by Big Scenes (Serenity) and familiar characters having kooky adventures (think the original Star Trek movie vs. its sequels). Your note made me realize for the first time that the Westerns I like also have this social experiment structure. I'm going to have to think about that a bit. It's surprising to hear so many people concerned about the actors' availability for additional episodes/movies. I'd be more concerned about the writer(s). The actors were fine, but not the heart of this series, which shocked me with how interesting it was -- and how hard it hooked my TV-loathing soul.