You select one of several graphics supplied with the game or create your own puzzle from any bitmap. When you select "new game", AlterJig scrambles the puzzle and challenges you to restore the picture by rotating groups of four tiles to get the tiles back to their proper position. Tile rotation is controlled by left and right mouse buttons. It sounds easier to solve than it is. There is a brief help file, but the demo mode helps you understand the game, which is pretty self-explanatory.