Use your mouse to draw objects for the ball to fall through. Press the play button to reset the ball. The ink meter shows how much more material you can draw. (The amount of squares is maxed out at 300 because Scratch has a limit on the number of clones that can exist at a time.) The ball will not interact with red pen, so make sure to fill in any cracks! To clear the material, just restart the project by clicking the green flag again. Have fun!