The object of the PanneRotto puzzle is to get all the same colored squares moved into the same colored boxes. Use the yellow target to move the outer cells around. Keep moving them strategically so that all of the same colored squares and boxes are matched up in the same cells. When you reach this target the puzzle is solved and you can continue to the next level of the puzzle.
It can take about 30 seconds to 1 minute to load the puzzle applet depending on the speed of your internet connection. Please be patient if it takes a while.