This puzzle is a classic design from years back. How many years? Heck if I know. The object is to move the 2x2 square piece from the upper left corner to the lower left corner. In theory, you can do this in 59 moves.
However, doing it in ANY number of moves is a proud achievement!
Slide Puzzle V3.5 Copyright © 1996-1999 Hirofumi Fujiwara, Nick Baxter