Here's a real one:
You are supervisor of a human colony on an alien planet- probably mars.
Building the colony is reminiscent of Sim City, but you must also manage the resources that keep your economy going. Extract ice and process and filter the water to provide helium to power the fusion generators to keep the lights on. Import foodstuffs long enough to get your own hydroponics going.
Not only must you put down the basic structures that keep your economy going, but you must also connect them. Citizens can only walk so far and mars rovers aren't the best way to transport water tanks! Everything from simple dirt roads to pressurized tunnels to transmission lines, maglev tracks, conveyor belts, pipes, and even landing pads and mass drivers is at your command- if you have the money, material, and manpower to build it.
You will also need the ability not only to grow, but to withstand the challenges you face in the wilderness: windstorms, mutiny, even sabotage. Combat is not the focus of the game, but making resilient systems is.
There are three generic goals to this game:
Profit: Getting profit on your colony's investment is key. When the colony fails or is retired, your total personal profit is a basic measure of how good you are- just like in real life!
Growth: Growing the colony into a thriving metropolis of happy and productive people is a key part of the game, and as the population grows, a more efficient and massive support structure is needed for them.
Industry: On this alien world, industrial process is tied with making the world more suitable for life. As your industry grows, so too does your ability to terraform the surface; perhaps making mars a second earth.
And, once you've tamed Mars, there's always the next challenge- Venus.