GBox Slide and Swap

Puzzle rectangular tags (also called Gem Puzzle, Boss Puzzle, Game of Fifteen, Mystic Square) and its variations, including a variant with pictures. The puzzle is a set of identical square tiles with numbers printed on them, lying in a rectangular box. One square field in the box remains empty. The goal of the game is to arrange the tiles in ascending order by moving them in the box, preferably with as few moves as possible.