Your nation has recently arrived on Mars. Violence has, of course, been banned on the red planet, but this does not stop you and your enemies from waging economic warfare through trade routes and economic assimilation. Your goal is to be the owner of every city on Mars.
You will do this by constructing cities, and trade routes between cities, to develop a strong economic foundation. When you're ready, you'll connect trade routes to your opponent's cities to begin your attack.
To create a city, you can click on one of your cities and drag to your destination. If the destination is open land, a new city will be created. If the destination is another of your cities, or one of your opponent's cities, only the route will be made. You can also create a city by clicking on open land, and dragging to one of your cities. This will create a trade route from the new city to your city.
Note as well that you have a resource bar at the bottom of the screen. Creating cities and trade routes takes resources. If the bar is too low, you'll be unable to make more.
Also note that you have a maximum distance to which you can make a new city from another city.
Your first goal is to create a network of cities trading with each other that helps each city become strong. You'll notice that the strength of the city is shown by the thickness of the blue or green ring around the city. Allowing your cities to trade with each other is paramount to success.
Your goal is to take over every one of your opponent's cities. Now that you know that making trade routes to one of your own cities makes it stronger, think of what it does to an opponent's city. A trade route gives you economic influence over their city. If you're influencing a city of theirs more than they are, you'll gain control of the city. Progress in doing this is noted in the color of the ring around a city. The rings are purely blue or green if only the owning player is influencing the city. The more a green city is under attack, the more it turns white. The more a blue city is under attack, the more it turns black.
Remember, though, that by sending a trade route to an opponent's city, you're actually strengthening the city. Make your attacks with prudence; good luck.