"Stretch your mind and test your perception at the very bounds of endurance. The simple premise of picture matching finds its ultimate realisation as you struggle to connect each picture with its mate against a steadily ticking clock. With a huge number of different images and more possible combinations than there are atoms in the universe, truly this is a game that only those with the strongest mental capacities can grapple with."
The game is an XNA version of the standard picture matching game. Drive the cursor around the screen and match up pairs of images against the clock.
You can find the game resources here.