A “videogame storybook about adventures in the sky”, where you control a cloud-bound boy.
Castles in the Sky is available to buy direct from the developers.
Castles in the Sky Review for Mac OS X
I was interested in Castles of the Sky after reading about it on Rock Paper Shotgun. In that review, Cara Ellison describes it as a profoundly moving experience. Intrigued, I contacted the developer, and launched the Mac version.