Slide the squares up/down and left/right to match the hint, which is a smooth gradient. If you slide a square to the right, the rightmost square wraps back around to the left, so the row loops on itself. Works really well on touch-screens. You don't have to lift your mouse or finger to do multiple moves, just keep dragging! Choose a board size of 2-10 (or edit the variable for a size up to 256!) (The frame rate is not the best, I would like to learn how to improve pen-shape drawing, so if you have any ideas, let me know)
This is similar to the classic slide-16 or sliding tile picture toys, also akin to the Rubik's Race or Square Up board games, the only difference being that these loop back around and there is no blank space. This is almost a direct clone of a program that Youtube creator [carykh] made in his video [How I made a 2D Rubik's Cube]: https://www.youtube.com/watch?v=95rtiz-V2zM