There are a few ways how to unwind a tired mind: have a bath, a quiet coffee break on the house roof, or play a simple puzzle game. Have a look at littlepeter Puzzle, a free sliding puzzle.
     littlepeter Puzzle is a puzzle where you have a square playfield divided up in equal tiles. The tiles comprise an image. At the beginning of the game all the tiles get shuffled and one tile goes missing so there is room for moving other ones about. The goal of the game is to restore the initial order of tiles by sliding them on the playfield so that you can see the original image. The less time and moves you spend on achieving that, the better result you'll have.
     The game has quite unusual controls: you slide the tiles with the keyboard arrows instead of moving them with a mouse cursor. But that's quite easy to get used to. The game also features different levels of difficulty, including a custom one. Download it today and see for yourself.