First click green flag.You can use arrow keys or mouse to control it.To use mouse (random drawing) click H key and to stop following the mouse click D key.To change the size of pen (to make it a brush) click C key. And to delete the drawings (you can only delete it by whole) click the space bar key.You can also make it move diagonally by holding right or left arrow key while holding down or up arrow key.
I made this on my own
