A technically excellent game marred by fundamentally broken story
It's like someone took the Mass Effect 3 ending and made an entire game out of it.
That's harsh, but I can explain: Mass Effect 3 was released a while back, the culmination of years of planning hundreds of gameplay hours. During the final sequence, the logical consistency breaks down, inexplicable character(s) are introduced, and everyone was left scratching their heads. Bioware stood behind their story, however, and released an extended cut, filling in the bits and pieces everyone at Bioware already understood.
What does this have to do with Halo 4? Everything. The folks at 343, like the ones at Bioware, live and breathe their franchise. They're exposed to it every single day. After a while, it blurs together, and visual cues develop their own shorthand, and a situation can be explained with less. It happens everywhere. In the workplace, it becomes jargon, and in-jokes. In a video game, it becomes Halo 4: A title that assumes you've spent the last 4 years working on it.
I'm sure at some point Halo 4's plot made sense. After that point though, someone took a large carving knife to it and divvied it up into all the bits and pieces of multimedia befitting such a storied franchise. It's broken up into books, vignettes, cutscenes, ambient dialogue, anime, content to validate Halo Waypoint, whatever. Taken together, I'm sure it's very impressive. Taken in the form of Halo 4, it's nonsense, and nonsense that has lost touch.
This is clear from the moment the antagonist is introduced, and Master Chief and Cortana refer to him by name before he even introduces himself. I played through the game in coop, and as a result had my subtitles on so I wouldn't miss anything. For a moment, I thought perhaps super-hacker Cortana somehow read my subtitles, which named the antagonist the first time he spoke off camera. That is a massive oversight, and disturbing that I had to make that mental leap to make the context of the game make sense.
Halo 4's plot is terrible, and a huge mess. It's pretty though, as is the rest of the game. So very, very pretty. The combat and AI are technically excellent, a high water mark for the genre. Cheers all around! There's really nothing else to say about it. It deserves 5 stars just for the systems in place and how much content you have access to: A full campaign, an endlessly replayable multiplayer mode with dozens of game types, and a groundbreaking episodic coop campaign as well. All top tier. It's a shame then that it has to be dragged down by the fragmented mess the campaign calls a plot.