Fantastic Contraption

Fun game, the goal is to get the pink circle (or whatever shape the it happens to be) to the pink goal area by connecting the pink object to wheels, and connecting the wheels with water rods, and wood rods. By creating geometric shapes you find a way to get the object to the goal.

The wiki for this game describes it like this:
Fantastic Contraption is a single player internet 'game' or puzzle. A problem scenario, known as a 'level', is presented along with assorted tools and the player has to build a machine (or contraption) in the blue workshop area to move a special red object into the pink goal to achieve victory.

This is one of those games that you can lose a good hour or two playing. I could see students using this to understand geometric shapes, and for learning problem solving skills.