You might want to check out "lyric games", they're built around pretty much exactly that premise. Here's a couple links to get you started:

https://itch.io/c/741014/lyric-games
https://www.dicebreaker.com/categori...tal-lyric-rpgs

I've also seen some writing from Yoko Ono connected to the idea of very very rules-light lyric games, c.f. here:

https://twitter.com/proton_31/status...48912691789824

I also really like the idea in the original post of a rules-heavy/crunchy game that's too unwieldy for play, but is something for people to talk about and dig into, maybe make characters with or discuss the interactions of the mechanics.