A strange little side quest
Put Sticky Balls next to the history of puzzles and a few unexpected connections appear. The name Tetris combines a reference to four-square pieces with Pajitnov's interest in tennis. The same trail leads to another fact: Pac-Man went on sale in 1980, and its creator Toru Iwatani famously linked the character's shape to a pizza with a slice missing. That gives Sticky Balls a little more company than it first appears to have.