A strange little side quest
Butterfly Shimai belongs to a much longer story of play than a browser tab might suggest. The name Tetris combines a reference to four-square pieces with Pajitnov's interest in tennis. The same trail leads to another fact: Street Fighter II, released in 1991, turned head-to-head arcade fighting into a worldwide phenomenon and helped define the modern fighting-game genre. That history is one reason familiar mechanics can still feel new when they are recombined well.