I don’t know what this game was originally called, but I adore it. I have recently played a point-and-click adventure game on Steam, and a certain part of the game had this exact mechanic, but the stones would change their color (between two total colors) when moved. It was a challenging yet great addition, and I adore how you approached this game so that stones are dark first, and they eventually get revealed as you pick them. Such an excellent job!