If you're looking to buy a game that doesn't cost too much and offers great looking visuals, then Limbo is for you. This puzzle-platform game is a sidescroller that has you controlling an unnamed boy who is searching for his sister. There's no soundtrack, it's in greyscale, and features some pretty gruesome deaths for your character.
In this tutorial, you'll be going after all the achievements that are in this short, but very sweet, game. There may be some spoilers in here just so you know. Good luck and enjoy!