At first glance, this game seems simple, because its essence can be expressed in only one sentence: click on the correct color. It’s not that simple: it is based on the Stroop effect, which is known in psychology as a delay in reaction influenced by reading words written in color that does not match the meaning of the written words. It takes longer to name the color of a word that is written in a different color and you are more prone to errors than when the color matches the name. Keep in mind that you have less than 2.3 seconds to select the right color, and with each level the time limit gets shorter. Thinking for too long can lead to a loss. This game is useful for developing the flexibility of cognitive thinking and productivity.