In the left part of the screen, click on
the chosen piece of the puzzle. If you change your mind, click on
an other piece.
Then, in the right part of the screen,
click on the square where you want to put the chosen piece. If you
change your mind, click on an other square.
To remove a piece from a previously
chosen square (right part of the screen), click on it.
To have a look at the model while
playing, click on the "Model" button.
Good luck !
(Photo : Sumeria, Wild Africa)