Synthesia

[Illidan]

http://www.synthesiagame.com/

It's pretty much the equivalent of Guitar Hero, if it were on Piano. It's fun, but pretty hard, unless you've figured out exactly which keys play which notes.

Free to play, but for the Learning Pack you've got to pay $20.

[Ad Bot]

[Sirrus]

If I had a midi keyboard I'd buy this.