Ok, this isn't a game, but rather an acustic guitar simulator. Still it is fun, and there are certain game aspects (unlocking content by playing songs). I picked this up when it was released yesterday, so my time with it is limited, but I'm already satisfied that I will get my moneys worth. You strum the strings using the touch-screen and select chords using the D-pad (or can be configured to use the buttons if you are a leftie). Obviously, you aren't going to learn proper fretting from this simulator, but if (like me) you've never learned to play guitar, this will allow you to get some of the satisfaction of playing your favorite songs. Within an hour, I was playing a recognizable version of the Marley classic "No Woman, No Cry" (at least I recognized it).
I'm giving the game 5 stars, but that doesn't mean it's perfect. The main downsides I see so far is that they only included 17 songs (plus 3 more you can unlock with a simple code). Not all of the songs will be recognized by most people, but everyone should know at least some of them. I can't imagine that they songs take up much space on the game card (just the lyrics, chords, and strumming patterns), so it is dissapointing that they didn't include more, but I guess they were constrained by licensing costs. It would also be great if they would let you download or enter your own lyrics and chords, but those features don't appear to be present either. Maybe version 2 :)
Update: After playing with the game a little more, I would probably change my score to 4 stars if I could. For some reason, they only included a playback mode on less than half the songs. The playback mode is useful when trying to learn an unfamiliar song. Again, I can't see that this would add tremendous amounts of data so it seems to me that this product was rushed out the door a little bit. Still, it's fun for what it is.