This week's DS on DS Review was written on LEGO Rock Band.
From the review: "When Guitar Hero first hit the Nintendo DS, it was fun to play, but only for short periods. That is all thanks to the hand cramping that everyone experienced with the required add-on controller that went in the GBA slot. Then, on top of that, the DSi was released and everyone who got one could no longer play any of the Guitar Hero games. Along comes LEGO Rock Band, and now it doesn't matter if you have a DS Lite or a DSi. You also don't need a goofy peripheral to play."
The full review can be read here:
http://www.digitalsomething.com/news/2637.html
