GBox Slide and Swap

Rectangular Puzzle Cards (also known as Gem Puzzle, Boss Puzzle, Fifteen Game, Mystery Square) and its variants, including a variant with pictures. The puzzle is a set of identical squares printed with numbers, placed in a rectangular box. One square field in the box remains empty. The object of the game is to arrange the tiles in ascending order by moving them around the box, preferably with as few moves as possible.