Daedalian Opus is an early puzzle game for the Game Boy where the player must solve jigsaw puzzles with pentominoes (5-block shapes instead of the familiar 4-block tetromino). The player is awarded new pieces to use periodically to help with the more complex later levels.
Jigwally solves this game's puzzles with custom software that employs the Dancing Links algorithm to find exact covers (solutions) for each jigsaw. The author analyzed and chose the overall fastest solution for each puzzle, and completed the game in record time.
This run can be seen played back on a real Game Boy Player here!