How to play
- Place one queen in every row, every column and every colored region.
- Queens can’t touch each other, not even at a corner.
- Tap a square once for ×, twice for a queen. Drag to mark × on several squares.
Keyboard: arrows move, space cycles, q queen, x cross out, backspace clears, h hint, Ctrl+Z undo, Ctrl+Shift+Z redo.
Learn the logic behind it