"Line Rider" in which the drawn line becomes a sliding course as it is

Very fun interactive toy made in Flash. The line drawn with the mouse becomes the course as it is, and the character runs on the sled on your hand made character. If you make it well, you can also have a pretty amazing course.

It is easy to understand when you actually touch it. Access is from the following.
Line Rider - beta by ~ fsk on deviantART

Press "Play" to start. Then click "Continue". A pure white canvas will appear, so click on the pencil icon and draw a line appropriately. Then click the play button to run over the line. When you click the trash can icon, the line disappears and you can do it again. It is quite interesting depending on the ingenuity.