Well, I just got it today as a Christmas present and began playing through the campaigns (I'm now at the Iron Legion Flashback part), and then I tried out the WiFi Battle Modes. Well, enough about what I did, here's my review on it so far.
Story: This game goes more into depth of the history of the nations in Battalion Wars, which was a relief, because the last game mentioned next to nothing on such details. The main plot is that, Kaiser Vlad has returned with a sinister scheme, starting rumors around the globe and turning the nations on each other like last time. (I guess the fool me twice rule doesn't work on these guys =P) What separates this from it's GCN predecessor is the most obvious notice ever! That, and the game is more diverse, meaning even the battlefields of the nations have their own theme about them, giving it that "this <insert object in game here> is my favorite!" kind of feel.
So, I give this a solid 10.00 because compared to the last game, this storyline actually has some density to it.
Gameplay: You will NEVER find a more intricate yet simplified style of warfare than what you can find on the Nintendo Wii's nunchuck and Wiimote. From barrel rolls, to diving and emerging subs, the nunchuck dictates most of the movement action. It's unique and takes quite a while to get the hang of, I stumble a bit on it myself, but I do much better than when I first tried. (I'm still used to the GCN Controls lol)
Gameplay, it's a 9.5 because damn, is it fun to play!
Graphics: While improved somewhat, the same graphics of the GCN is back. Except that it's more enhanced than it's cousin. I'm talking about, when it rains, there are water droplets hitting your screen like a window... Yeah, it's that in depth.
They've also traded voice actors for some of the beloved chars, and added some new characters as well. There's evens-and-odds in the graphics of this game, some features impressed me, but, most was the same old.
Graphics, I must give a 5.7
This is my review so far, I will add more stuff later on.
Seriously, it's a good game for you Advance War/Battalion War Fans, GET IT!