While waiting for BrowserShots to load some views, I was checking out the public history and got led to the Osu! website. Osu is along similar line to the (Insert-Instrument-Here)Hero games. You download "beatmaps", which coordinate certain actions to parts of music. The more accurately you complete the actions, the more points you get. Despite being slightly repulsed by the pink overload, I decided to give it a try. While even some of the easier beatmaps can be a little challenging, at least if you get a few actions stacked on each other, it's a fun sort of challenge.
On a slight sidenote, Osu is tracked by Evolve. :)