To successfully complete a puzzle, you must solve it with a limited number of moves. This number appears each time you begin a puzzle, for example: “Complete the puzzle in less than 15 moves”.
A move is a swap between two pieces. If you move the same piece several times, it counts for that many moves. However, bonuses do not count as moves. The Magnetallows you to move a piece but it does not reduce the number of moves you have left. Throughout your game session, the number on the left side of the “Pause” button tells you how many moves you have left.
The move limit changes from one puzzle to another, depending on their complexity. The more complex a puzzle is, the more moves are available.