Phun is without question the greatest computer toy in the history of the universe, if this had been around when I was a kid I would be a frickin genius by now. You don’t need things any more. It’s extremely easy to use. As a starter tip, turn gravity off when you’re attaching stuff to the background (right click after selecting “affix” tool).
Very cool. Get your Phun (2D physics software) for free. Phun is a Master of Science Theises by Computing Science student Emil Ernerfeldt.