In spite of big hits like Guitar Hero or Singstar, games completely designed upon music as a central element are still quite rare. There are wonderful ideas out there by independent designers and even some great indy games occasianally noticed during development competitions. We actually wonder why not more game developers jump the train and utilize the emotion and immersion that tieing music close to the game design brings to gameplay.
Recently a casual game called Audiosurf hit the market (mainly via Steam) and showed again, how easy it is to boost a simple racing/puzzle game to new heights by tieing the design to music. The player can choose any mp3 from his computer and the game will calculate a racetrack synched to the music. Collecting colored blocks along the way earns the player points. The big fun here is that the arrangement of the blocks as well as the design of the whole racing track is individually calculated for each song and thus the player hits the blocks in synch to the music. Playing this game with your favorite music is just pure fun. It can also be very relaxing (if done in chill out mode) during a coffee break at your work desk.
We at Hans HiScore hope that more game developers pick up the idea of music as a central game design element and we're looking forward to the wonderful games to be thought up out there...