I just came across a very addictive game called Crayon Physics.  The game has a fun look and feel using crayon drawings for the graphics.  I love it!  You can draw items on the screen and those items seem to come to life and have all of the physical constraints that you would expect.  If you draw a round object on the form, it will fall to the ground taking down anything in its path.   The current version of the game can be downloaded and run from the url below.  I made it to the 5th level in about an hour and I have played it over and over and over again because it is just so cool and fun.  Let me know if you find the game as addictive as I did.

http://www.kloonigames.com/blog/games/crayon/