Save The Universe is a 90 page scifi or science-fantasy rpg in the style of Star Wars. It's very well-written and more about storytelling than beating the mechanics, but even more than either of those things it's about collaborating with the people at your table to create the setting as you play it.
Because it's setting-neutral, you can use it to play Star Wars or Mass Effect or Firefly. Or you can use it to play anything else if you're willing to do the worldbuilding legwork, and the book does a lot to support and simplify that process.
It does, however, broadly expect you to have a cast of scrappy, complex heroes and a ship, and it expects you to work against a vast and entrenched Enemy. You could theoretically run it without either of those things, but there's less support for that.
Visuals-wise, Save The Universe doesn't have interior art, but its layout is extremely clear and easy to read, and the rules are clearly explained and super easy to follow.
Mechanically, Save The Universe feels a little similar to Blades In The Dark or Cthulhu Dark, but it's very distinctly its own thing. You roll a pair of d6s, and different numbers cause each die to succeed if certain conditions are met. These conditions might include being in good health, having specific character class features, having support, etc, and it's pretty common for a typical character on a typical roll to have a lot of these conditions met. Either way, if one die succeeds, that's a complicated success. If both do, it's a clean success. Complications and failures can revert progress clocks, cause damage, or introduce other dangers, as in Blades. Unlike Blades, PCs' health is easy to damage but recovers fully whenever you get a decent rest. Furthermore, damage never kills you. It just takes you out of action.
Character creation is fairly meaty, but a lot of it is determining your character's fluff and their place in the setting. This is all done deliberately, not through random rolls, and it feels like by the end of the creation process you have a solidly deep understanding of who you're playing.
Also, a lot of tools and prompts are provided to help you build and flesh out your own setting (if you want to use a custom setting,) and these make up a lot of the book's pagecount, so if reading 90 pages to use the system is a deal-breaker, you need to read way, way less than that if your game takes place in a pre-established universe. The world-building tools are also really solid, so if you and your group do enjoy collaborative world-creation, I would strongly advise checking them out.
GMs in particular will find a lot of support from this game, and I think I'd strongly recommend it to first-time GMs for its GM tools alone. There's advice for creating scenarios without vastly overspending effort. There's ways to calibrate the game to different lengths of play, including one-shots and sequential campaigns. In general, the advice assumes you don't have infinite time and energy, and that you're looking for options that split speed/ease/effectiveness pretty evenly.
It also does a really good job at predicting potential problems and snares, and teaching you how to avoid them before they can happen---and I'm giving this its own paragraph because I've never seen a game say "avoid making all complications problems for the current scene, you'll bog things down. Kick some complications down the road to be trouble later" before. And it's *really* essential advice in games that tends towards succeed-with-a-complication.
Past the GM section, there's sample scenarios and settings, all of which feel solidly fleshed and written, but at this point the tl;dr is: this is a very well-made game. Its first visual impression isn't grabbing, but everything beneath that is rock solid, and if you like Blades, Fate, PbtA, or have a scifi epic that you want to collaborate with your players on, I would strongly recommend buying a copy of this.