Click the green flag and enjoy the op art. Then look inside and try changing the variable values. It's a lot of fun even if you don't understand what they do :)
My only contribution here is changing the color a bit. If you like this, go show your appreciation for the original project, where you will also find an explanation of how the project generates such a cool pattern. Before seeing the original project, I knew noting about Victor Vasarely or op art, but now I do. Thanks @Scratch-Minion! You can learn too: https://en.wikipedia.org/wiki/Victor_Vasarely https://en.wikipedia.org/wiki/Op_art