Retrobet
Retrobet is the 1907 two-pile duel of Willem Wythoff, rebuilt as a cold neon reactor you fight turn by turn. Two charge piles are drawn as a single chess queen standing on a grid; the goal node waits at the bottom-left origin. On your turn you slide the queen straight left, straight down, or diagonally down-left - that is, drain any amount from one pile, or an equal amount from both. Whoever lands on the origin and takes the last charge wins. It sounds simple, and it is - until you meet the reactor. Hidden across the grid are "cold" squares: leave the queen on one and a perfect opponent cannot recover. Twenty nodes rise in difficulty, and the reactor sharpens as you climb, from a forgiving early spar to flawless cold-square play at the deepest nodes. There is exactly one winning line, and learning to find it is the whole game - real strategy, no luck, no timers forcing your hand. Clear nodes cleanly and quickly for three diamonds and vault charges. Everything is earned through skill; nothing is sold. A pure, honest test of a century-old idea.
Retrobet - two piles, one queen, take the last