Want a 5-minute game that has great tunes? Then RB : U is for you. Great songs and great use of PSP for a music game.
Rock Band Unplugged allows me to carry this wherever I go, and once you start playing Move Along, it gets highly addictive, especially if you can master the Very Hard levels. With other great songs like What's My Age Again?, Mr Brightside, Where'd You Go?, Kryptonite, Alive, etc. the only issue I have is it's limited 40 plus track list. Of course more can be downloaded but it would be great if it had 70+ to start off like it's bigger brother versions.
A better storyline would be notch my rating up further instead of a generic world tour mode. Other than that, I won't hesitate to recommend this wonderful gem to anyone's PSP collection.