• ✓Number nine on the brain-game shortlist (docs/brain-game-roadmap.md)
• ✓Not a mirror-drawing puzzle: that is a picture of symmetry. This is symmetry doing work
• ✓The strategy: level the rows, then copy their move in the other row. No looking ahead at all
• ✓The bot plays perfectly: one that blundered would let a child win by luck and confirm nothing
• ✓The last level starts balanced, so the player is lost from move one — the method has a precondition
• ✓The theory is verified exhaustively over 144 positions — the player to move wins iff the rows differ — and the bot lost none of 400 games from a balanced start
• ✓A three-row mode, where the rule becomes XOR rather than plain equalityplanned

✓ = done · ☐ = planned. Every game is built one step at a time like this.