If you are curious about the puzzle, keep reading.
We can make an interesting puzzle game out of the two intersecting wheels above. Imagine that we can randomly spin the wheels clockwise or counterclockwise, even after a relatively small number of rotations it may be quite a challenge to go backward and get to the original position.
Below two types of handles are set on the wheels.
The first type set on the center of each wheel allows you to rotate it counterclockwise, this is the shape of such a handle:
The second type set on the left and right top corners allows you to rotate each wheel clockwise, this is the shape of such a handle:
Use the image below to familiarize yourself with how it all works. Click on the handles and see the effects. Clicking six times consecutively on the same handle will bring you back to the starting point. Clicking on the center handle and then on the corner handle for the same wheel will also bring you back to the starting point. You can always reload the page if you ever get lost.
I want to mention that his puzzle game was originally invented by Doug Engel, who also has many other interesting inventions which can be seen here.
Once you are familiar with the handles you may want to try a first level of challenges, by clicking here.