Wait for it to load. Play around with the gobo (controls = arrow keys). Admire the pretty landscape. Press the green flag to generate a new landscape. Repeat the above steps. If you want you can press space to toggle ball mode. It turns the gobo into a ball which rolls around. Same controls. You can also use the mouse to drag it around and throw it at walls.
Edit: Interestingly, I hadn't seen any of the other similar projects to this before I made it. Promise I didn't copy! Scolling Version: http://scratch.mit.edu/projects/18425757/ -------------------------------------------------------------------------------------------------- All me. Inspired by http://scratch.mit.edu/projects/10420540/ Draws the terrain using the pen by cloning the pen sprite into 32 times and making each clone concentrate on its own little 32nd of the screen before withering up and dying. A very sad and short-lived experience. Before I used this technique it took ages to load. Each random landscape is basically a glorified y=sin(x) curve.