Does anyone remember the "Left Behind" series of novels? They were a rather cheesy bit of Christian fiction based around the author's interpretation of the Revelation of John and the other prophetic books of the Bible, and what happens after the "rapture". At one point a video game was made based on those novels, and it was just a crappy cookie-cutter RTS that, thankfully, sold poorly. The game really puzzled me because of it's lack of ambition. At the time I really wished that they'd made something like a post-apocalyptic Animal Crossing instead. In the books the city of Chicago is bombed, and the underground Christian resistance hacks government computers to trick people into thinking that nuclear bombs were used and the entire city is radioactive. They then set up their base amidst the ruins of Chicago. Imagine a setting where you run errands for people while exploring a bombed out metropolis for supplies. Collect items to furnish your base however you like, unlock new modes of transportation, etc.
Now I'm thinking it'd be more fun to make a steampunk version of animal crossing. Picture a steampunk universe where there's a town built to be a think-tank of quirky and eccentric scientists (kind of like the SyFy series Eureka), and you play a bike messenger just hired. You run errands, help with experiments, find lost parts after explosions, provide first aid, build robots, celebrate holidays, work your way up to better jobs, etc. All the while you're upgrading your own living quarters, from a tiny little one-room pre-fab, up until you've got a nice townhouse, or maybe even a mansion. You get furnishings, and inventions to play with. I think something like that could be amazing.