Apollo4X is essentially a game about buying and selling goods between planets, making and spending profits, and fighting a defensive war against an oncoming enemy. Think of it as a mashup of a trade-tycoon, 4X sci-fi, and a card battle game. The business part is an abstraction of true market cause-and-effect forces, which you of course exploit, and play politics with. Political gains unlock new abilities and military units. Over-expansion is held in check by the cultural demands of your colonists. The game is inspired directly the the historical East India Trading Company's exploits in business, politics, and military imperialism - but in space, because spaceships are way cooler than merchant clippers.