You just said the game play style or 'genre,' my friend. It is a management "sim" game.
I can agree it could fall under a "sim" title, but I think the term "sim" is bloated. Most games "simulate" something else. Battlefield is a sim game, in the sense that it simulates shooting. But the general mechanic is shooting, and so the game is a shooter.
But since the game play mechanics for the title "management sim" could vary so much, it renders the genre title useless in describing its game play.
My general belief, is that if all I read was the Genre, I should know something about how that game is played. I.e. Shooter, Racing, Side Scroller. These all tell me about how the game is played.
I agree sim is a bloated term, hence all the quotation marks and clarifications. I totally agree, that if a game simulates combat, or playing an instrument, or any individual's action, it's not considered a "sim" game, and we could go into whether or not action games actually have the intent of simulating combat, when they usually take very large liberties in favor of providing what they are actually known for when more realism/fidelity is possible, but I digress, let's just stick to management, then.
While the theming for management games varies WILDLY, the actual mechanics seem to be pretty consistent. What is the huge difference, mechanically, between, say, Zynga's Street Racing and, I don't know, Sim City? In both cases, you use your resources to purchase assets that vary in terms of theme, cost and adjustments to the simulation, then you let the simulation run and see what resources you've acquired. Then you make more purchases and run the simulation again. Most have an 'events' mechanic, with both positive and negative themed events that occur seemingly at random and/or tied to the storyline. In every case, the mechanics seem to be about not controlling individuals, but systems. Once a game is about controlling and placing individuals, the emphasis on that makes it more of an RTS-style where instead of letting the simulation run, you can 'micro' in order to turn the simulation into something where your 'macro' management isn't the deciding factor in the outcome.
Those are my thoughts, anyway, it's possible that I'm not as aware of the mechanics involved in these games, since I haven't played many since SimAnt, though, now that I think about it... that was definitely an RTS.