Best DS game I have EVER played! Music is great, difficulty is perfect, and gameplay is addictive!
Music- 9/10. There are good songs (Without a fight, Makes no Difference, and many more) and bad songs (Believe and Material Girl to name a few) but the good songs helped with the score. There are 19 songs, which is a letdown when you've completed them all, but it's still fun to re-play them. You can save Replay data and scores too! Also, they don't use the original versions, which is also a letdown.
Difficulty: 10/10 4 different difficulties gives you many different experiences. You start with easy ones then unlock harder ones. You get used to the difficuties fast.
graphics: 8/10 Not that good, but better than Guitar Hero in my opinion. Touch screen has normal DS graphics, but the top screen is much better. Not Xbox or PS3 graphics, but good for DS.
gameplay: 10/10 To simplify things, I would say addictive and fun.
Overall: 9.5/10 There are some letdowns, but we can ignore them. All I have to say is this: buy it, it is the BEST DS game I have EVER played!