Shuffle is a simple but challenging little puzzle.
The goal of Shuffle is to press the switch buttons (A, B, C, D) until the cells are arranged in order (0, 1, 2, 3, 4, 5, 6, 7, 8).
If you play at difficulty X, the puzzle can be solved in X or fewer moves. Shuffle was written as an excuse to do animation on PalmOS.
I first saw it as a curses-based BSD application long ago.
