An absolutely amazing game, especially if you are like me and love the logistics behind things, ie working out how to make complex systems function efficently, or just at all. This game is not for those who do not like complexity, it is for those who see it as a challenge to take on. Don't get me wrong this game also makes use of your time management skills and inner childish love of destruction, as the ever growing pollution of your base angers the indigenous wildlife (constantly mutanting and growing bugs/ aliens) and they begin to attack. I can not think of a better game that offers that puzzle like problem solving that I first found playing minecraft tekkit. If you want a real challenge after completing the base game, I recommend Bob's Mods, a modpack (just google it) I just started playing and it is so far amazingly even more complex and dangerous than the base game. Love this game and its 100+ hours of content, especially with the ease to install mods and the avalibility of mods from the community.
The music is also excellent and fits very well with the atmosphere of the game.