I found it the other day when I was looking around for some cool games. It's really sick and is better than most games I've seen in stores. It combines RTS, MMO, FPS, and some other stuff into one game and does a pretty damn good job of it. I'd definitely try it out, it's addicting though and games last a while. Go through the tutorial first and then I'd practice to get used to the different units.
Best free game ever!