So this application is like Little Big Planet in concept. Watch these Youtube videos to ge a idea of what you do in this game.
Phun- 2D physics sandbox
http://www.youtube.com/watch?v=0H5g9VS0ENM Downfall of the Citadel
http://www.youtube.com/watch?v=VpAUv7cImpABasically you create whatever you want. It's a good time waster, and keeps your right brain stimulated. Ok I just needed to say stimulated today (crosses out stimulated on things to say list).
Looks like something fun to do when you have time to burn. Too bad it's not multiplayer yet. I can see some fun with doing a game of tower distruction, or something.
Edit: Maybe I'll add this to MG's thread as I think his pc can run this.
Edit: You MUST watch all of the first vid. The end with the water is cool. When you create your own you can have a huge area full of water. It look so awesome. Then you can add whatever and relive your toys in bath tub moments.