Checkout Scratch at MIT. http://scratch.mit.edu/ It is a more visual way of dragging and dropping code statements. It is centered around moving sprites arround on the screen. When they are done it will publish there project to the gallary at the Scratch site so they can share there creation with there friends. I found it to incorporate many concepts in ways kids can understand, including xy courdinate and moving sprites, variables, control statements, collision detection, broadcasting/listenting for events. I was able to teach my son concepts of mutlti threading and syncronization because each sprite gets its own script which is running concurrently. By using the event broadcasting and listenting I was able to show him how to sychronize actions between different sprites.