Since 1995, Ocean Quigly has gone from artist, to art director, to creative directer for the Sim City series. But in his interview with Gamasutra, he talks like he's been designing since 1940. The latest in the series promises a modern city of structural integrity, where the aesthetic is drawn from relationship between each human cog, which he promises will be seen and not read, shown and not told. Of course, this doesn't limit your city to utopian beauty—your simulation of a more 21st-century city deliberately rigged for entropic catastrophe also counts, if that's what you're into.
So, for example, we could have people in a house get sick for no reason. They go to the hospital and get cured, but that's kind of unsatisfying. You'd rather bind the fact that they got sick to something that is in principle, and hopefully in practice, understandable and parse-able by the player, right?
If they got sick, maybe they got sick because a patient zero came into the city and carried a disease with them. Or maybe they got sick because they drank polluted water. Or maybe they got sick because they lived downwind from the toxic chemicals of an industrial plant.
And so the simulation aesthetic is about drawing the cause-and-effect relationships between things and giving them integrity the player can understand, and not just doing things as smoke-and-mirrors, but having it be like a watch, where all the gears visibly move the other gears forward and the whole thing has got an integrity -- almost a mechanical integrity of all the pieces stacking into each other and moving each other in a way that the player can understand.