Here you draw ramps to help your motorcycle to overcome a challenge, usually a long jump. Try to reach as far as possible! It's about drawing track chunks before and after the jump, and the goal is to reach as far as possible with your jump. Your earlier marks will be visible in green color, the last one in white color, and you have to try to go farther.
Keep the left mouse button pressed to draw by moving it on the scene. When you complete a track, click the button 'GO'.