I don't know if it's because I'm getting older, or ADD, or what, but I want to see a new IP in this category. Everything is sequels now, and y'know, that's FINE to an extent. But I want a strategy sim that makes me go "Wow, never saw that before!" or "I'm surprised it took someone this long to make a game about this." I'm not sure what that game would be, or I might attempt to make it myself (with the help of coder friends, so it probably wouldn't happen as they have enough on their plates.)
Years ago my wife and I were designing a game called "Mall Mogul," it was going to look basically similar to RCT3 or Planet Coaster in terms of animations and people detail, but with a 3D view through security cameras where everything would be rendered in more realistic detail, just because. (No strategic reason for it at the time, we just wanted an excuse to have a somewhat realistic realtime rendering of a mall.) Then "Mall Tycoon" came out, and while it was a far lesser experience than the pipedream we were concocting, it was similar enough to dissuade us from continuing it, plus our reference material was dying out anyway. (We were visiting as many malls as possible to get an idea how the "average" mall would look.)
I think what I'm saying is I'd like to see the Planet Coaster/Planet Zoo people make a Planet Mall.