Here's a couple of interesting blogs doing the rounds just now. They are trying to dig into what RPG rules actually do and why people are seemingly quite content to use "wrong" systems for the games they play:
https://seraphim-seraphina.itch.io/my-blog/devlog/1200662/what-do-we-mean-when-we-say-a-game-supports-play
You can tell us how it went tomorrow afternoon.
I've run Offworlders a lot for both kids and adults, I think it's basically the perfect SF RPG for one shots.
I've even written four adventures for it, although not to the extent that I could publish them.
It's worse than that. In the original PS1 you had the first story then the second, which were different stories, but also they both changed depending on which character you selected to play first.