How to play
Put the numbers in order, with the empty space last.Tap a tile next to the empty space to slide it. Arrow keys or WASD move an adjacent tile in that direction. Every shuffle is made from legal moves, so every board can be solved. Undo lets you reconsider a move.
Choose 3×3 for a short puzzle or 4×4 for a longer challenge. Best move counts are stored separately for each size.