(completed puzzle)
This is the classic Free Online Sliding Tile Puzzle Game. Click with your mouse on a game tile to move it, you can only move tiles onto adjacent vacant squares. Continue sliding game tiles until the image is formed.
A sliding puzzle, sliding block puzzle, or sliding tile puzzle challenges a player to slide usually flat pieces along certain routes to establish a certain end-configuration.
Unlike other tour puzzles, a sliding block puzzle prohibits lifting any piece off the board. This property separates sliding puzzles from rearrangement puzzles. Hence finding moves, and the paths opened up by each move, within the two-dimensional confines of the board, are important parts of solving sliding block puzzles.
Sliding puzzles are essentially two-dimensional in nature, even if the sliding is facilitated by mechanically interlinked pieces (like partially encaged marbles) or three-dimensional tokens.