Guess the Correlation is a game with a rather self-explanatory name that is designed to test your mathematical aptitude.
The game requires you to look at a scatter plot graph, and work out the correlation coefficient in your mind. If your guess is somewhere in the general region of the correct answer, you are rewarded for your efforts with a 'life'. If you're far off, you lose a life. It's an incredibly simple game design, and is designed to test your ability to spot mathematical trends.
Guess the Correlation will surely appeal to mathematics geeks who also happen to enjoy intellectually challenging video games. Video games are often depicted as being based around violence or sports, but this particular game shows that geeks of the most socially peculiar variety -- those who love math -- can also enjoy games that appear to have been tailored specifically to them.