Cloud (aka That Cloud Game) is a fascinating free game developed and distributed by students at USC majoring in multimedia production. It takes the inspiration for its gameplay mechanics from the maddeningly addictive Katamari Damacy, but replaces the madcap strangeness of Katamari with a more calm, contemplative aesthetic.
If you like the music in Cloud, you can download it in MP3 format, too. How cool is that?
(Also — if you enjoyed Katamari Damacy, the sequel, We ♥ Katamari, has just been released. And if you never played Katamari Damacy… well then, goddammit, you need to play Katamari Damacy already. Yes, it’s that good.)