A strange little side quest
A little context makes Tower Defence 2D more fun to place on the gaming map. The word 'checkmate' is linked to the Persian expression 'shah mat', used when the king was trapped. The same trail leads to another fact: In 1958, Tennis for Two used an analog computer and an oscilloscope to turn simple physics into a playable tennis-like demonstration. That gives Tower Defence 2D a little more company than it first appears to have.