15 Puzzle Game (by Dalmax) description

The classic 15-puzzle game (also called Gem Puzzle, Boss Puzzle, Game of Fifteen, Mystic Square and many others) is a sliding puzzle that consists of a frame of numbered square tiles in random order with one tile missing.

The object of the puzzle is to place the tiles in order (with the "hole" in the lower-right corner) by making sliding moves that use the empty space.