Shorter than I thought it would be, but very deep. Every action has deep ripples through the story. The game is clever about its mechanics, and never once forced me to suspend of disbelief. I was thoroughly hooked by every part of the story, and it does a lot to place you in its universe. Some examples include letting you put your real email in at the start so you can receive emails updating you about in-world events, or giving you designated points to "log off" from the network if you'd like to stop playing for the real-world day. (Of course, you can still quit the game whenever and your progress is saved)
I really enjoyed the game.