You have to shift the pieces, so that you get the numbers in the correct order. The required number is shown by a gray number, when the piece is shifted away. When you click on one of the outer fields, then the pieces of the inner fields will be shifted in the direction to the field which you have clicked on. You can also use the arrow keys and the space bar for this game.

Here you have to turn the positions of the pieces with the numbers 1, 3 and 4, then the game is solved.
All games excepting the "small" and "hexagonal" ones are relatively hard to solve, however every game can be solved !