Atfer playing some more, I finaly have a playthrough where I managed to survive. That said, I had to reload 3-4 times because I lost some crucial soldiers. So I think the difficulty is good, but like I mentioned in my other thread (Level Restriction for equipment really needed?) I would like to have a good chance to make a comeback once I lose some of my better soldiers. Right now, there is no chance to make a comeback when you lose your best guys.