Out of this World.
The mechanics of the puzzles have no gimmick. No portal gun, no time manipulation. It is incredibly simple. This simplicity offers the most organic, and rewarding puzzle-platforming I've ever experienced. Nothing is ever arbitrary. Limbo is about observation and logical thinking. If your gung-ho, you will die often and be left cringing at a little boy that is decapitated very gruesomely.
The game is designed on the backbone of minimalism. Sounds are sparse and music is faint. But the sound design is magnificent and key to arguably the most atmospheric game this generation. There is no story, at first. The more you think about it, discuss it and analyze, the more you realize how expertly it is told. Everything blends so seamlessly in this game. No direct levels, emotion exerted through movement, depth of field are examples of the extreme fluidity of the game. This game is one of the best games this year, and arguably, one of the most important experiences for games an artistic medium.