The scenario quickly becomes addictive, very addictive, I rarely played as long a row in a game (I'm up before 7am trafficked during rainy weekends, it will NEVER happen to me in normal times ). And the game length is perfect, About 40 hours in my case, so we have something to put in their mouths. I have not done the multi-mission, it does not interest me, but it is truly optional. I played it on easy, it is frankly good (I will surely try again one day in normal mode), even if like me you are a little not good gamepad.
I honestly think this is the best game I've ever played, because we really vibrates with his character. And we feel the urgency underlying this atmosphere of doom, with some side that suggest Battlestar Galactica (refugees everywhere, the mess, the anguish of the civilians ...). And yet I am not, at base, a fan of shooting missions in third person where the goal is to kill everything that moves (I have no desire to play Call of Duty or Gears of War). But there it is so well done, I could that adhering.
In short, you like the space opera, you love SF, you love that your decisions have an impact on your environment, well, even if you do not like the GST, go ahead. Eyes closed. Promised.