Wait—it says "blue," but it s printed in red. What s going on This multi-player brainteaser game is designed to befuddle, and strenghten your brain. Everyone plays at once as you race to match up cards that don t match—it sounds easy, but it s surprisingly challenging. None of a Kind is based on The Stroop Test, one of the most-cited papers in experimental psychology. It studies the relationship between the brain s processing speed and executive functions, focusing on regions of the brain involved in planning, decision-making, and managing real-world interference, such as multi-tasking. In other words, playing None of a Kind improves your brain s processing speed!