Goal: Swap the populations of balls so that the blue balls are in the bottom wooden block and the orange ones are in the top wooden block.
Press on the next image to enlarge it. Then, you can download it and play it (the large image contains the game definition).
You can see the configuration of the game in the next two screens. The first one shows the initial positions of the interactive objects. The second one shows the rest of parameters: type of interaction, type of visualization, and behaviour of the red, green and blue colours in the scenario.