If you press left arrow key, the mouse is going to turn -90 degree and going to left side. If you press right arrow key, it is going to turn 90 degree and going to right side. If you press up arrow key, it is going to turn 0 degree and going to up side. If you press down arrow key, it is going to turn 180 degree and going to down side. If you press space key, it will say "Hello!." If you press any key, it is going to change the color.
Put the four separate event blocks corresponding to each of the arrow keys. Add the appropriate point in direction block and move [10] steps block to each event block. Add two other event blocks that react to different user input.