Use arrow keys or mobile to stretch the shape. How does it work? For starters, there are two large squares that move relative of each other. If you look inside the code, their movement is actually quite simple. Secondly, there are 8 small sprites on the corners of the large squares. They follow the squares and always stick to the corners. You cannot see them because their ghost effect is at 100. Lastly, a pen block connects the small squares using the pen extension. Whenever the squares move, the pen moves. Altogether, this creates the illusion of 3d