Well, when compared to the other two Big screen Pokemon games, it's terrible. Whereas, PC and PXDGoD were BRILLIANT, possibly the best games out around at their times, when I bought this, I played through it for a bit, and now it's gathering dust in my game cupboard. That's my opinion though.
But yeah, if you just want a 3D battle screen with absolutely no story or reasoning to it, or anything other than just battling, go ahead and buy it, you'll love it.