The "game" is absolutely absorbing. The atmosphere drags the player in and doesn't let go. You have to be aware of things changing all the time, who to talk to, who not to kill etc. Every time you load a saved game, the disposition of the AI NPC's will be different, so Tactics are really on-the-fly.
The Multiplayer section, while offering the usual suspects, is great. The atmosphere, the tactics are all refined. More folks should play online, though many Mods preclude you from doing so.
I just hope with attention being payed to the "Clear Skies" release, that attention to the present game goes by the way-side (Patch 1.00004 GCS)!!!!