Winner of the 2006 IGF Student Showcase, Cloud was made by a group students from the University of Southern California. It's a very original - and brilliantly executed - game where you control clouds, fly through them and use them to make interesting shapes. From the game's website:
"Most video game today is about addiction. But for Cloud, it is designed to be something you can put down and go back to enjoy your life at any time. No failure, no saving. You pick it up and leave it with no second thoughts"
I must say, it is much more complex approach than my own take on cloud manipulation in Insular.