Press the Space key to clear the screen, press up and down arrows to choose a color press the "S" and "H" keys to show and hide the color guide, use the mouse to draw, number 7 is an eraser.
This was just me experimenting again with scratch's pen feature. I figured out how to draw with the mouse and decided to make a project that lets you draw. This didn't take long to make but it was fun to do.