Halo 4 lets you down, in more ways than one.
In the first mission of Halo 4, you need to launch a missile from the Dawn to blow up a Covenant ship. Then you are swept into this sequence where the Dawn is compromised, and you must escape. When I played through this mission the first time, it was undoubtedly exhilarating. On my second play-through, however, I noticed something odd…the Covenant ship. Its explosion seemed rather off. But due to it being on Legendary, I paid it no mind and kept playing; relieved I had finally got through the first mission. Upon my return to that scene, I play the analyst. I watched every movement, every particle. Lo and behold, what I found gave me a feeling of vague emptiness. The Covenant ship that you blow up… doesn't blow up; it just sort of falls apart like a Lego set. That is not at all what I would expect a real spaceship to do when hit with a gigantic missile. It's just low quality. If you own the game, I suggest that you go and look for yourself.
This one, relatively small flaw is not enough to garner my annoyance though. But then, as I played on, these little flaws started popping up everywhere: patches of texture, fully rendered, looked dull and cloudy. Little details that I love looking for in other Halo games just weren't there. (The game I have is not broken in any way, these flaws are just there)
Even the multiplayer, which Halo games have always had a unique place on the shelf, has adopted the run-of-the-mill rank-up-to-get-better-stuff-for-your-player scheme. In previous installments, anyone could jump into a game of Halo and have some degree of freedom. No longer is that the case. The action is too fast paced, too tight, too intense. It's like I'm a real soldier, and this is my mission, and I must get it done. Man, I just want to play the game. I get that soldiering feeling in the campaign. The high adrenaline action is great, but it's either that or nothing at all.
343 Industries has made a mock-up, not a masterpiece, like they said it would be. Instead of setting the bar higher, the people at 343 have said 'Oh, well, it's our first game, so we'll take it easy'.
Now, this may seem like nit picking, but is it really nit picking to say that "I wanted two mediums one of each flavor, and you gave me a two-topping pizza". (A bad analogy, but please bear with me and assume that two mediums equals one large.) They may be the same flavor, but one choice has much less work involved. That is what Halo 4 is like; flashy, but not fully flavored.
In conclusion, Halo 4 delivers on story and narrative, but in everything else it either falls short or goes over the top.