THE BEST PSP GAME. PERIOD.
1. game length. there is no limit to the amount of hours you can put into this game, i have never liked a rythm game before but i got it at an import shop and that was when it came out. and i still suck!!!. there are countless hours you can play this game due to the large amount of songs. this game is freaking impossible to master and i dont think i ever will master it.
2. unlocking stuff. unlocking characters, skins, and notes all take a lonnnnggggg tiimee. i have like 4 or 5 of each and theres 20 in each total to be unlocked. and if you unlock them you have to save up gold for a long time to be able to purchase them but the songs are so good and you can play over and over again. theres also a mission mode with 3 or so songs and you have to accomplish a certain amount of points, combo, or other things to pass them. it took me forever to pass the first mission and theres over 30 so far its impossible to describe the huge amount of content on this game and how freaking amazing it is BUY IT NOW