[disclosure: I playtested this product and was compensated as an illustrator in the published version. I was not asked to write this review.]
If you've been looking for sci-fi mechanics in the 5e style, this is it.
Combat has been overhauled to focus on ranged fighting, with mechanics that make cover valuable, recontextualizes old abilities to value indirect damage or utility in a gunfight, and builds a suite of new abilities around this new system of combat. New classes and alternative versions of old classes give a suite of options to the new ranged combat. Melee fighting is still a viable choice, but the risks of doing so inform the payoffs of pushing up into someone's face. My favorite class is the rework of the Barbarian as the "Vanguard", a nanite-enhanced melee fighter who influences technology simply by being nearby. I personally don't usually go in for detailed spellcasting classes, but the new casting-focused options (Psion, Scientist, Oracle) have a lot of depth in their casting that can be explored.
The spaceship combat is my personal favorite throughout the TTRPGs that I've played. It focuses on a role-based style of running a spaceship, where everybody has something to do- the basic setup is pilot/mechanic/gunner/hacker, with room to flex around. These rules scale up and down from capital ships with whole crews to worry about to fighters that get more tricks and manuvers to play with. On the freighters and transports where most parties will be, though, it feels like the classic sci-fi scrappy hunk of junk that you're fixing and running around in on the fly.
The 13 new playable races ("species", here) give a lot of options to engage with the game. There's weird one-eyed dwarves with retractable eyestalks, deep-sea mermaids with mallable skin, big bug people with four arms... and there aren't any uncomfortable hangups here on a certain species being fundamentally evil. Instead, there's the reality of a complex setting, where old politics and wars inform the influence civilizations had on the galaxy and other species at large. Well, there's that, and a malevolent empire of humans from outside the galaxy that regularly threatens to end civilization, but I personally feel like it's about time we got around to that plotline as a community.
The setting itself has a wide range of detail and inspiration to support campaigns spanning the whole sci-fi gamut. Even if you have your own galaxy planned out, I'd recommend looking through the writings here on the worlds and species of S&S's setting.
Spaceships and Starwyrms is ready to go. I'm looking forward to the future.