I don't know if you've already got it or not, but this is what I have to say about the game:
While the game is short, it's an amazing, emotion-filled experience. I've finished the game countless times, just for the heck of it, while helping out and guiding people who were either playing for the first time or hunting for glyphs.
Never has a PS3 game managed to make me cry, but I was overwhelmed near the end of the game (for those who've already played it, I'm referring to the end of the snow stage, and all the way to the game's ending from there). Thatgamecompany is quickly becoming my favorite indie developer.
Without a single line of dialogue, this game triggered a powerful emotional response in most people I've spoken to that played this game. The music is amazing, well-placed, and definitely helps setting the mood.
Yeah its that type of game that gives you an indescribable but positive feeling on the inside while playing. It almost makes you feel "connected" to the character and the game.
I think it is the lack of descriptions for anything, allowing you to imagine what is going on, that truly does it.