I was blown away.
This game had one of the best dialog in a flash game. Ever. Period.
When you are in a room, and your future self is exclaiming that he is in a room filled with bodies of himself, or that he is in hell, or there is something growing out of his brain, or your past selves ask for help on certain levels, it gives it an awesome atmosphere.
But anyway, onto the gameplay. It is good, and the learning curve is good, but the concept gets kind of boring after you get to the later levels with no new elements, but the story keeps you going, even after you die, and shout fcuk for the -fh time.
The music? It is okay, but it gets annoying after a few hours of hearing it.
Never tried the other features, but the singleplayer is enough to give this game a ten.