My favourite game by far. Endless replay-ability, so much content, so many things you can do, each time you play is different and unpredictable, and if you get bored there are 2 huge dlcs you can buy. Get bored after that? This game has probably the best modding community I've ever seen. You want something? 9 times out of 10 there's a mod for it.
If you like colony-builder games, stop reading reviews. Just buy it. Trust me.