TwinCol

Games for your brain, indeed... and also addictive! Follow the squares of colors and patterns, and match them up by clicking on pairs. Seems easy enough, right? Try getting up to level 6, where the squares are moving across the panel at a fast pace, and intersecting with each other. Careful; some colors may look alike, but will have different patterns.

http://www.gamesforthebrain.com/game/twincol/