Music Monstars is a new music game developed by Novarama and published by JoWood Ibérica and Tivola, which combines the gameplay styles of Ouendan with instrument-simulating music games like Jam Sessions and Band Brothers in an interesting way. Notes are played by tapping shrinking circles on the screen as in Ouendan, but those circles correspond to keyboard keys, drums, or guitar strings in such a way that players play the song in the game by tapping. Eventually, then, it could be possible to play the song without the "assistance" of the circles.
But to really see why Music Monstars is awesome, watch the above video. Then have a look at the two after the break. We really, really hope it gets released outside of Europe (but with the band Europe intact).