Awesome! Will definitely check it out. In case you haven’t seen it, here’s a nice collection of tips for indie game devs: https://develop.games
(I realize this reads as a bot comment, lol, but that’s a genuine tip, and that website isn’t even monetised as far as I know).
DCSS[1] would alone probably take five years to master.
Dwarf Fortress (although I haven’t really played it myself yet).
And, of course, Factorio, that with existing mods has probably enough content for the rest of my life.
Chimera Squad and Hi-Fi Rush jump to mind — is that the sort of thing you have in mind?