That's awesome you played for so long! Honestly, when the game was originally made I didn't think people would be spending nearly so much time with it, so there isn't really a "late game" at all yet! That's the first thing on my list right now for future updates, to add new characters and storylines that get added on as your city grows.
I played for 3h until I had done all the stories (I think), including Project L.A.P.I.N., the videogame maker, the gold generating machine, curing chester, geordie sacrifice, trees protests, etc. I reached something like 10k people and 6k gold, but there is no more use to it sadly ;)
If there were more stories and the possibility to save progress, I would surely continue!