Fun. Some but not all of the levels are challenging, good music, pretty easy to learn to play, lots of factions with different personalities.
A lot of improvements are probably possible, but the thing I think I'd most like to see is a less "expendable" attitude toward allies. At the end of nearly every mission you have to turn against any allies you have, so you never really feel like you have strong, long-term partnerships. Still, very good game.