The game is very challenging and gives you lots of different puzzles that sometimes can blow your mind. The more important is the way that you're given all that puzzles. The game does not lead you by the hand, it even doesn't tell you what are actually puzzles. You should open your mind and all your feelings to reach the end.
I would like to tell more but I'm afraid I can spoil something (or I've already done it).

I played this game a year ago and still haven't find any puzzle game that so big, so different and gives such incredible experience. Once I completed it, my first thought was: "I want to forget all that I know about this game and play it once again".

The game is very challenging and gives you lots of different puzzles that sometimes can blow your mind. The more important is the way that you're given all that puzzles. The game does not lead you by the hand, it even doesn't tell you what are actually puzzles. You should open your mind and all your feelings to reach the end. I would like to tell more but I'm afraid I can spoil something (or I've already done it). I played this game a year ago and still haven't find any puzzle game that so big, so different and gives such incredible experience. Once I completed it, my first thought was: "I want to forget all that I know about this game and play it once again".