We kind of take Call of Duty for granted now, don't we? With it's yearly releases and over-the-top, explosion-filled stories, I think we've come to treat the single player experience as a silly byproduct to the multiplayer. But really, if you think about it, CoD has always cared about story. From its first remarkable cinematic representation of World War II, to that scene in CoD 4, the series has been experimenting with narrative since its inception. Black Ops II lives up to that pedigree by doing something fairly interesting with its narrative. Now, the story itself never quite reaches the levels of intensity that some of its predecessors accomplished, but it gets bonus points for trying something new.
This is, obviously, a First Person Shooter; an action game wrapped in a thriller full of intrigue and danger on a global scale. It's what we've come to expect from the series. CoD's action structure - particularly that of the later games in the series - complements the narrative style; each mission takes the player to a different exotic location or, in this case, a different time. The pacing works well within that framework; a cut-scene or briefing sequence preludes an action-filled mission, which ends in another cut-scene, and so on. It makes the game story very easy to control.
There are game-related problems with this kind of rigid frame structure - most notably that it ends up being awfully dull as the game becomes way too repetitive. To alleviate this, BOII's missions will usually include a gimmick or two to freshen things up (such as swinging across a cliff, wing-suit flying, or playing for a moment as a rage-infused psychopath).
Regardless of the repetitive gameplay, this structure seems perfectly suited to telling a story in a game - and it is, in a way. The problem this game faces is the same problem that all narrative-led games must face - balancing game-length with story-length. One of the challenges of creating stories for video games is that the story needs to be able to accommodate the obligatory amount of game time. Since the game's main story is independent of the game's world, they both operate in a different time, so to speak. That's why many games have side-quests and optional missions; to make a game more worthwhile, developers try to find ways to prolong the game experience without damaging the integrity of its story.
BOII has a crack at this - there are a few optional missions that go along and affect the main story, but for the most part the main storyline is the only one we have. BOII's frame structure doesn't allow for a lot of deviations. Unfortunately, what this means here is that a lot of the game's plot is pure filler. This includes playing multiple characters, in different times and places - all without it being necessary to the plot. To mask all this filler material, the game's briefing sections are presented in a tense Tony Scott style shaky-cam, the characters blabbering a hectic hodgepodge of names of people and places you can't possibly hope to remember, and practically none of which matter later on. The point of this, it seems, is to disorient the player with a tidal wave of supposedly important information in an attempt to imbue the mission with purpose. It makes the missions feel relevant even though they're not, and the developers manage to squeeze in another 30 minutes' worth of game time.
It's not the most elegant of ways to solve the story/game balance problem, to say the least. It's a shame, too, because a lot of the elements in the game could have been used for something more than just filler. For example, in one level you get to play as the villain. Think of the possibilities! Not many games offer the experience of playing from multiple perspectives, and as a narrative tool it's woefully underused. Alas, here it ends up as merely one of the aforementioned gimmicks. You play a level in a slightly different way to how you usually play. Game-wise it's refreshing but, again, offers nothing substantial to the plot. To be fair, there does seem to be some commentary about the villain's motivation; there is an attempt to humanize a type of character that is usually depicted as monstrous. As far as this level design is concerned, however, there is no play on points of view, no use of dramatic irony. Nothing. It's a wasted opportunity.
So yeah, BOII's story is nothing to write home about. Despite the lackluster presentation, however, the story does have a saving grace: its branching plot structure. It is by far the most intriguing aspect of the game's story. I'm not usually partial to multiple-end narratives - I find that allowing the player to affect a game's story does more harm than good to the plot - but I do like what they did with the mechanic in this game. The only other game I could think of that does something similar is Heavy Rain. The way the game's plot proceeds, then, is determined by the player's actions. Certain characters may live or die, missions succeed or fail, depending entirely on how the player performs in the level. I like this method because it is feels more authentic and organic than simply offering the player a clear "choice" between options A and B. Another reason this method is interesting is because the actions that affect the plot in a "good" way are directly related to how well the player plays. In this sense, the plot branching acts as a kind of scoring system; the better you play, the better the ending you get. That's why this method kind of works - because there's a correlation between wanting to play well and wanting a good ending.
I say "kind of works" because even though this is a very innovative approach to storytelling (and scoring, for that matter), it's essentially anchoring the story to a game mechanic. I prefer to be free to enjoy a game's story without having my experience of it hinge upon my gaming prowess. Ultimately, I believe the story would be better off with a single plot that actually used all of its characters in an interesting way within the narrative, rather than use them as part of a complex system to indicate whether I've played well or not.