White Star Galaxy Edition (WS-GE) is a fun, white box, OSR science fiction game. It follows the White Box design theory, where we only use the d20 and a d6 dice, and all the others are ignored. No d4 dice to step on, no d8, no d10, and no d12. This is all White Box compatible, so any fantasy implementation of the rules is an instant expansion set.
And we don't need all those funny dice! I love them, but there is something very clean and simple about a game that just uses the d20 and the d6, a feeling of streamlined elegance and simplicity. What die do I roll? Well, you have two choices. One it used for to-hits and saves, and the other one is used for everything else. Considering the average rolls of the 4d, d8, d10, and d12 are mostly a few points off the d6, a flat modifier takes care of all the variance you would ever need.
Also note, in true White Box games there is no d10 or d100, so those huge d100 charts are out of the question. If you need a lot of chart results, use a d20 and be choosy about your table entries, or just for a d66 for 36 results and that should be plenty. A d40, d60, d120, or d400 is also possible if you get creative with two dice.
You could mix this with White Box FMAG and double your monster list, and have a bunch of fun "low tech world" stuff to expand your game with. The magic works, too. It all works. Unlike today's games where they purposefully make the rules incompatible with everything else, White Box just works, and it works with every other White Box game.
And the game has this space adventure feeling, sort of a mix of Star Wars, Spaceballs, Star Crash, Battle Beyond the Stars, Guardians of the Galaxy, the Buck Rogers TV show, and any low-budget 1980s science fiction you would find on random cable channels.
And this is "class and level" science fiction, where you are gaining hit points and blasting higher level monsters as your adventures go up the level chart. This is like "straightforward Starfinder" without the 3.5E or PF2 rules, and it just works well and plays fast. And there is no magic! We have psionic power like gifts here. If you want space magic, pull it in from the fantasy game. It just works.
And both WS-GE and WB FMAG use the single saving throw mechanic, eliminating those strange saving throw charts for a single saving throw number (modified by internal or external circumstances).
And there are plenty of expansion books to collect for this game, with tons of options. This is 0e science fiction role playing at its best, completely compatible, it doesn't take itself too seriously, and it has fun with the idea. The game has good "star knights" and evil "void knights" who wield "star swords." It is a campy take on some of the science fiction tropes, but, I kind of like that in a "this is generic science fiction way" and I could come to accept the idea as something cool.
If it keeps creators writing these types of stories and out of hot water with IP holders, than the generic replacement is far superior to the original inspiration. Plus, we are free to take these ideas in our own directions and tell our stories with them, and not just "do what the rights holders allows us to do." Maybe the old "IP names" were "lost to the past" and these are the new and accepted names for the protectors of the galaxy. In the future, 600 years later, they are star knights now, and the old words are looked down upon or lost to time.
It is cool.
Make the universe your own.