The Call of the Fireflies is a puzzle-based singleplayer mod for Crysis. There's no guns, explosions or nanosuits involved. Just an old man who follows mysterious fireflies through mountains and dark caves, sleeping villages and frozen woods, and has to use all kinds of mechanisms to open his path, while battling to stay alive in the winter cold.
I don´t know where to begin, the level design, the atmosphere, the gameplay. It´s all so well done, you can´t help wondering how much effort mustn´t have been put in to this. Refreshing and never really frustrating. Well done! :)