To say that Bungie had a successful run with Halo would be an understatement, so 343 Industries had a very high bar to meet after taking over the franchise. The single-player falters at delivering on an experience of equal caliber to previous entries, but there is still an amazing amount of great extended content crammed into this box.
Halo 4 picks up roughly five years after we last inhabited everyone's favorite Spartan as Master Chief and the artificial intelligence Cortana have been adrift on the remains of the Forward Unto Dawn frigate since the events ending Halo 3. As chance would have it, they eventually encounter the shield world Requiem, which houses the Forerunner known as the Didact. He's got a bone to pick with humanity, and his Promethean forces have attracted the attention of a rebel sect of Covenant and the UNSC Infinity. If this is all a bit confusing, it's because many of these elements have only ever been alluded to or briefly mentioned in the games - Halo 4 makes use of the series' extended canon from various books and miniseries. At times it's a good addition; it's interesting to see this greater depth being given to the story, like the shady ethics behind the creation of the Spartans and how AIs break down after seven years but Cortana has been online for eight. However, relying on other media also hurts Halo 4's story in places. Master Chief meeting with the now Captain Thomas Lasky is shown in a way that suggests some significance, which can be confusing if you haven't watched the Forward Unto Dawn miniseries.
At times, the story is great; the interaction between Cortana and Chief is perhaps the best it's ever been, with the lumbering stoic trying to come to terms with one of his only friends losing her sanity. Sadly, the rest of the supporting cast is not nearly as well-written. The captain of the Infinity, for example, seems to exist solely to contradict Master Chief regardless of common sense or whether it makes for good military strategy. Instead of a cohesive narrative, it feels as if characters are making decisions simply to move the plot forward or provide an excuse for the next big fight.
However, the biggest disappointment in the single player is how, at times, it just doesn't feel like Halo. Aesthetically, many small things have been changed to give the game a more grounded or realistic look. To be fair, Bungie even did this a bit themselves, but all the little things, like plasma grenades and weapons fire being much smaller, makes the game feel not quite right. The game's soundtrack is also a letdown. The loss of Martin O'Donnell and Michael Salvatori, composers on the previous games, is quite apparent and profound. While those are certainly big shoes to fill, the new score lacks any of the punch and gravitas from the originals. There's something to be said about not repeating what's been done, but the music in Halo 4 is often just subtle ambiance, if it's even there at all. It simply doesn't have a Halo feel at all to be tearing through Covenant with your massive tank without some strong percussion driving the experience.
Thankfully, much of the gameplay has remained the same. Enemies are more than just waves of mooks to gun down, and defeating them almost always requires some kind of trick or tactic. Halo 4 introduces a whole new set of enemies, the Prometheans, and they all have their own quirks and weaknesses that you'll need to learn. Watchers, the flying robots, are particularly challenging as they do everything from shield other enemies, resurrect fallen allies and even toss your grenades around. These actions don't seem like much, but the varied tactics helps keep fights interesting as you're constantly thrown into encounters that can't be won simply by shooting from behind cover. There are even new weapons to try, though a lot of the Promethean's weapons just feel like laser versions of ordinary shotguns, assault rifles, and so forth.