story telling with clouds

Have you seen those projectors that spin around and project shapes on the walls of children's rooms? I'm thinking about making something that starts off projecting an amorphous cloud shape on a wall. There's a box with a pressure sensor on each side. When someone touches the sensor the clouds changes shape, so you can make an animal, building, heart or whatever shape you want. When you are done creating you can blow on another sensor and have the shape detach and start rotating around the wall. Then another cloud shape appears ready for you to shape. You could use this to tell a bedtime story or count sheep before you go to sleep.