As far as combinations of music and games, this is as good as it gets.
Music is truly at the heart of Sound Shapes. On the surface, it plays as a classic platformer but the true joy in playing comes from how your actions influence the music you are hearing. It is easy to breeze through most levels w/o dying but Sound Shapes provides plenty of additional difficulty by challenging the player to collect all the floating nodes w/in a stage--referred to as notes, in-game. Rather than collecting these notes being a reward unto itself, the gamer is rewarded by getting to hear additional layers of the background musiv. This added aspect combines the hypnotic qualities of digging deep into a rhythm game to the classic platformer mechanics.
While this combination is satisfying on its own, what really puts Sound Shapes a cut above is the quality of its music and artwork. Each stage features a different visual and music artist. Probably not everyone will be enamoured w/ every single included track but the combinations of artists seems well thought out and purposeful. I, for one, was not a huge fan of the music by Deadmau5 but it's hard to argue it didn't fit well w/ the 8-bit retro themed art by Pixeljam. My personal favorite for both artwork and music were the Superbrothers/Jim Gutherie levels which had the look and sound of the Sword & Sworcery EP w/ the far superior gameplay of Sound Shapes. Beck's musical contributions were also a highlight and I felt like two out of three of his songs were about two minutes of Beck's surrealist rapping short of being hit singles.
This stuff makes for a great game on its own but Sound Shapes really goes above in beyond in it's extra features--if you even want to call them that as they could easily be a game unto themselvesf. For starters, once the game is completed you get some additional challenges in the form of the extremely difficult death mode and beat school which also serves as something of a tutorial for using the very robust level creation tool, which are also included. There are already quite a few user created levels available for download now and while none of them yet reaches quite the quality of the provided levels, the potential for a virtually infinite pool of new experiences is enticing to say the least.