The book re-uses many of the familiar tropes in tabletop RPGs. I think that Stars Without Number does an excellent job of not only remaining faithful to those tropes, but to add its own flavor into the mix. The storylines involving the use of psychics to effect interstellar space, with a unique twist, was my favorite bit.
"Magic" is kinda Vancian. Ability scores are based on D&D (Strength, Charisma, etc). The encounter generation table is quite useful, even outside of this setting.
I'd recommend this book. You should download it. And why not? It's free. Even if you don't run an encounter using this setting, there's enough material here that it can be inserted into almost any Sci-Fi based rules system, like Serenity, RIFTS, or Starfinder.
[5 of 5 Stars!]