Singstar for those who like HSM...basically
It contains all of the songs from high school musical 1 and 2, and also some further additional songs from other popular disney movies/disney stars. These unlockable songs are better, in my opinion, than those of high school musical.
It is relatively easy to unlock everything, as you just have to pick one song which you are relatively good at, sing it enough times and hey presto! you've unlocked everything.
The graphics, choice of characters and stages are all pretty poor. And all of the songs are covers.
It's a good game if you and your friend(s) are sad enough to know the words to HSM, but if you aren't, it's still relatively amusing. For better songs try singstar. And for better disney songs, try Disney Sing It!