The goal of this game is to make only one large loop, by swaping/rotating pieces.
By clicking one piece, it rotates 1/4 turn.
A drag and drop exchanges pieces at origin and destination of the drag.
"Replay" restarts the same game. "New game" ... a new different game, at random.
The changed pieces are grayed. (note that some pieces just "seem to" change by rotation, their topological connections don't. In such a case, they are not grayed, the rotation changes nothing in any path)
Solution (initial start position)
For all other positions, you have to find the solution by yourself. The program just paints and counts the loops.