Folks, you'll want to grab a copy of Rebel Galaxy. It captures the Firefly feel nicely, has Southern Rock for the soundtrack, and comes from people behind Diablo 2, Fate, Mythus, and Torchlight 1&2. It's single player, doesn't rely on story, and you can largely play it your way. Join the pirates for faction ships and gear (or kill pirate lords for some dropped gear), join the Merchant and Mercenary Guilds, earn reputation, trade, mine, run blockades, bust blockades, whatever you want! It's the best $20 you can spend on Steam and GoG.