If you are looking for another game with the same feel, try Case of the Golden Idol. I genuinely thought it was the same developer until I looked it up.

I don’t agree with the idea of wholesale copying all of reddit, but I really do like the idea of creating an instance and copying all the subreddits as empty communities, and then each of these communities can point people to the Lemmy equivalents (and block all other content).

The question is who would do this and how would it be curated?

The way that steam handles paid reactions seems fine to me.