Serenity is based on the TV miniseries Firefly, but the story is a standalone but i would recommend watching Firefly first.
Earth that was could no longer sustain the number of people there were just too many so they had to find a new solar system with dozens of planets and hundreds of moons, each one terraformed, a process taking decades to support human life to become new Earths. The central planets of this solar system formed the Alliance rules by an interplanetary parliament but the savage outer planets refused Alliance control causing a war which the alliance won.
From its great concept to the fantastic decor & aesthetics, this movie kept me engaged with a simple but decent plot, good acting with Alan Tudyk & Nathan Fillion, good dialogue, and an overall retrospace vibe that i love.
