If you click the green flag, you'll see a rotating tear drop upper left corner. It's representing the current status of the pen. Click anywhere and drag to draw your favorite picture. Enjoy!
Type 'r' key to toggle the rotation of the pen. Type 'p' key to toggle the pen status indicator. Type left or right arrow key to change the angle of the pen. Type up or down key to change the color of the pen. Type SPACE key to erase all.
