As a fan of the anime and songs, you can be sure to love this game. Adorable and fun, definitely worth checking out.
Gameplay
It's a rhythm game, what else can be said? Pretty much, you're just pressing the correct buttons when needed to. You start out with one difficulty per song, normal. As you clear a song, you'll unlock "Hard" for that specific song. The game consists of 19 songs only. However, even with a small amount of songs, for each songs, you can choose to play as the Lead Guitar(Yui), Rhythm Guitar(Azusa), Drums(Ritsu), Keyboard(Tsumugi), and Bass(Mio). 5 different note charts for each song. You can do the math. After selecting your character, you can choose an item(food). These items can either multiply your score for a limited amount of time, make the song easier, etc. If hard isn't enough, once you clear any song without getting a "miss" or "bad", you unlock an item which makes the song even harder. The game might already be hard enough for some people, but one can easily get used to it.
If you're not playing a song, then you can go to the menu, where you can see chibi versions of the girls in their classroom, walking around doing random stuff. Quite adorable I must say. You can unlock items for the room you might be in, costumes to dress up the girls in, and items that could trigger a cute cutscene(such as the popular "Un-tan" from Yui). If you don't understand Japanese, you can still enjoy the gameplay, although you might want to look up a walkthrough for the scenes, and other stuff.
Graphics
Impressive for the PSP. Anime-like 3D design. Very colorful and it stands out. Nothing too awesome, but pretty good. The design on some of the costumes and the girls are really good.
Music
Obviously, all songs are in Japanese. If you enjoy J-pop you might like these songs as well. Can't say the same for newcomers to the J-pop world, or anime world. Then again, the game is intended for fans of the show, and anime fans.
Overall, a great game. As I said before, fans will simply love this game. A Must get for the fans, and a game worth checking out for anime fans.