Green colored squares appear on the field and then disappear. The player's task is, after the green squares have disappeared, to click with the mouse in the places where they were. If successful, the player goes to the next level, where the size of the playing field and the number of green squares increase. If the player makes a mistake 2 times, then he goes back 1 level. This automatically adjusts the difficulty. This game can be played indefinitely.
The effect of the game is that during the game the working memory of a person is trained. A good working memory is the key to success in intellectual activity.