There are two types of rewards you can get by completing the expansion puzzles:
• A new piece to your supply, including Ghost Pieces;
• Instant Level Up that lets you upgrade a piece in your supply one level up for or two levels up for . You can use this reward to upgrade up to a Ghost Piece (level-5 piece). With the Level up reward, you can upgrade pieces in your supply, including those you just took back from the completed puzzle.