Most awesomest game I have ever played. Took me a while to suss out the resources, but now I'm just addicted. Buy it!
It's really convenient how you can zoom right out, and the strategic overlay (If that's what it's called) is handy, although really you need a big screen for it to be effective. It's also pretty cool how you can choose victory conditions and adapt usable units. You can win by killing the primary command unit, destroying all buildings etc. You can also disable things like nukes and heavy artillery, to make it a good old fashioned troop battle.
Can't say too much about the campaign, I haven't played enough of it to comment properly, but from what I've played, it seems pretty good. Only thing that disappointed me was the lack of a fully operational official map editor. I'm not saying there isn't one available, but I can't find one.
Overall, the game definitely justifies its price and I would happily pay double the RRP for it.