A strange little side quest
Between one round of Impossible Tic Tac Toe and the next, this is worth knowing: The name Tetris combines a reference to four-square pieces with Pajitnov's interest in tennis. A second detail makes the picture even better: Nintendo's Donkey Kong arrived in 1981 and introduced the character first known as Jumpman, who later became Mario. The details change, but the appeal of learning a system and trying again is remarkably persistent.