1 - Set the starting position with the single pieces (image objects) spread all over the place
2 - Define the end position of all pieces (rectangle objects, or other image objects: make them somewhat visible to your end user)
3 - Select each image object in starting position, go to the "Actions" panel and choose "on touch down" event. then add the drag action: under the "drag" preferences establish the "drop" area and trigger a "move" action to position the image in the correct position, and outside the "drop" zone trigger a "move" action to report the image at the starting position....easy ;-)
