Sliding Puzzle

This is the sliding tile puzzle in its classic form. A grid of numbered tiles has one empty square, and the only move is to slide a neighbouring tile into it. The goal is to put the numbers back in order. Nothing else is needed to explain it, which is why the format has lasted as long as it has.

The game offers three board sizes: 3×3, 4×4 and 5×5. The small board is a warm-up that can be solved by feel; the larger ones are where method starts to matter, because moving one tile into place tends to disturb the ones you already fixed. Progressive levels lead from one to the next.

Two extras are worth knowing about. Custom themes change the look of the board, and an AI auto-solve can finish a position for you, which is handy for seeing how a stuck board untangles. What you are getting is the familiar puzzle, cleanly presented. What you are not getting is a new rule.

1. Pick a grid: 3x3, 4x4 or 5x5.
2. Slide a tile next to the empty space into it.
3. Keep moving tiles until the numbers read in order.
4. Use the auto-solve if you want to see how a position resolves.

Solve the top row first, then the left column, and treat what remains as a smaller puzzle. Working in that order stops finished tiles from being pulled back out of place.