It's about chess; it moves horizontally, vertically, diagonally, like moves on a chessboard. The individual panels have black and white backgrounds, like a ches

It's about chess; it moves horizontally, vertically, diagonally, like moves on a chessboard. The individual panels have black and white backgrounds, like a chessboard, which combined with the movement, gives him the chance to affect the mood; if he sticks to diagonal moves on black, you get a sequence of dark, moody frames. He also wrote, in the introduction to the comic (http://www.scottmccloud.com/1-webcomics/chess/index.html http://www.scottmccloud.com/1-webcomics/chess/index.html): My fourth online comic seemed to strike a chord with many readers, despite requiring side-scrolling as well as down-scrolling (which I'll admit, can be pretty annoying). It sounds like this was something experimental; remember, this was the early days of webcomics. He was experimenting with what you could do in a new medium. It turns out that this choice was kind of annoying; but it was a nice experiment, and it's a good comic despite the somewhat annoying scrolling.