Expansive.
They just keep getting better. The thing that sets this apart from the rest of the series is the way all of the environments were flawlessly linked together, with things happening in multiple places all coming together to create a lovely story. I also loved all of the little tidbits added in that serve to create a universe to have your characters act in, such as all the random posters, and the "dissenter be damned" and "failure is unacceptable" things. Simply great. I'm hoping that guy at the end is some sort of G-Man type character. The G-Man rules your soul. Bow to the G-Man, for he is master of your destiny.