Fun game with great graphics. Games are generally quick and contain a nice balance of strategy and luck. The only slight downside is that the game is almost always won by the first player to gain a 2+ advantage in bonus units.

Edit: As with others, I'm tacking on another star because the more I play, the more I enjoy playing. I've also seen a couple of comebacks from being down 2 bonus units - still difficult to do but not impossible.