The characters were mostly Western stereotypes who mostly talked like a Joss Whedon post, including savage Indians. The more educated or urban the characters, the more contemptible or villainous they were. (The only significant exception was a "girl" who spouted the dreariest mad libs imaginable.) The background, social, political or physical, made no sense whatsoever. The characters did not often interact with each other. They gave no hint they existed offscreen. They merely alternated spouting one liners. The hero kicked a prisoner into a jet engine in the first episode, which shows how sophisticated the humor was. Nevertheless, on one level the show was meant to be quite serious!
The series was quite obviously about how a handful of die hard Confederates ended up winning the Civil War after all. The movie Serenity jumped into the first stage of the end game.