A strange little side quest
One reason puzzles keeps producing good game ideas around Number Merging is that its history is full of strange turns. Alexey Pajitnov created Tetris in 1984 after drawing inspiration from pentomino puzzles, then simplified the idea around shapes made from four squares. The same trail leads to another fact: Atari's Gran Trak 10 from 1974 is recognized as the first arcade racing video game. That history is one reason familiar mechanics can still feel new when they are recombined well.
