Spring

Just take a look at the screenshots. Wonderful, isn't it? And this is exactly the way how it's played. By the way, Spring is a remake of older commercial realtime strategy Total Annihilation, which is played even today, almost ten years after releasing. And I have to admit that it's probably even more entertaining, mainly because of the quantity of new mods and enhanced multiplayer. Unfortunately the singleplayer part of Spring isn't worth saying, you can just play skirmish with more or less dumb bots, which I found quite boring. Anyway if you like strategy games and your PC is good enough to run Spring well, this is definetly the right choice!