- Cult Classic: The movie didn't perform very well financially, but it is almost universally loved among the show's original fans.
- Crosses the Line Twice: included in the blooper reel is an extra take of the shot in which Mal orders his crew to mask their ship as a Reaver's. The original scene is very nearly a Kick the Dog scene, but the moment Mal's improvised orders change from the script is the moment that he takes the line and guts it with a screwdriver.
"Put Book front and center; he's our friend, we should honor him. Kaylee, find that kid who's taking a dirt-nap with baby Jesus — we need a hood ornament. Jayne! Try not to steal too much of their shit!"
- Ear Worm: Fruity Oaty Bars.
- Fanon Discontinuity: Believe it or not, some fans of Firefly refuse to acknowledge this film's existence primarily because they refuse to accept Wash and Book's deaths.
- Fridge Brilliance: See the page.
- Hell Is That Noise: Reaver ships constantly broadcast the sound of dozens (possibly hundreds) of people screaming.
- Hilarious in Hindsight: Jayne snaps at River, uttering "I'll show her good and all, I got man parts" in "Trash". Fast forward to the Curb-Stomp Battle of Maidenhead, and...
- Memetic Mutation: "Ceiling River is Watching You Have Sex."
- Moral Event Horizon: The Operative's destruction/massacre of anywhere/anyone Serenity might go to for help.
- Retroactive Recognition: Solomon Northup is the Operative.
- They Changed It, Now It Sucks: Some fans of Firefly were not pleased that the "space western" elements from the TV show were dropped in favor of a more traditional sci-fi feel. This is ignoring the fact that many entire episodes of Firefly were largely sci-fi and had little "western" to themnote and the entire intro sequence of the movie was as pure "space western" as you could get.
- Uncanny Valley: This is where the lovedoll designers of the future are situated.
- The Woobie: Both River and Simon.