Thanks!
I had thought about adding some simple roll tables for NPCs, encounters, ect. But I don't want to tie it to any setting or genre. I might just add a few tools to help a GM incorporate it into their story, like a list of vague hooks or reasons why the PCs might sit down to play. I could also add optional rules to make it a gm-less one-shot rpg in itself.
Any feedback you want to share is welcome.