This is an extra Tuesday issue of this webcomic.
The image may be downloaded in higher resolutions:
Products. Some products are available based on this “Difficulty Levels” comic. These products use a revised version of the image that has more bold lines for better clarity when printed on products. See these online shops:
Three illustrations are positioned along the curve.
At the lower left corner of the chart, at the beginning of the curve, is the first illustration: a tic-tac-toe game in progress.
Approximately at the middle of the x axis, and slightly higher than the tic-tac-toe game, is the second illustration: a chessboard with a game in progress.
At the end of the curve, and positioned near the top right corner of the quadrant, is the third illustration: an outline of a stylized heart symbol.
The approximately-exponential-curve is solid throughout except that it is interrupted by the three illustrations so as not to overlap them, and it becomes a dashed line close to the heart symbol.
Title: Difficulty Levels.