With some three dozen books (consisting of novels and comic and reference books), a handful of live-action and animated short films, and almost a dozen main and spin-off games flying underneath the Halo banner, there can be no doubt that Halo is a franchise that has transcended far beyond its original medium. Much like the pre-Disney acquisition Star Wars universe, Halo's lore is no longer entirely driven by the actions of the main characters of the overall series, with quite a number of other characters going off on their own adventures across the galaxy. For example, Halo Wars 2, Microsoft's latest attempt to expand the story of Halo beyond the tale of Master Chief and Cortana, revolves around a long lost ship and her crew, with only the briefest mention of the Master Chief during its moderately long campaign.
Naturally, this is quite a boon for those who are interested in the story of Halo, especially with Halo Wars 2 featuring an in-game encyclopedia of sorts that offers insight into virtually every unit, event, and faction that makes an appearance in the game. You would have to suspend disbelief at times, as some things don't make much sense from a logical standpoint (Halo Wars 2 would've been a much shorter game if the Banished decided to actually use that fancy Assault Carrier of theirs), but then again that is almost a prerequisite to any game or movie involving aliens. In any case, most Halo fans would probably appreciate 343 Industries' attempts at exploring all of the other facets of the Halo universe, from shedding some light on the enigmatic Forerunners to showcasing all of the other battles and events that took place while the Master Chief was busy blowing up Halos.
Unfortunately, as fascinating as all these new plot points may be, there are two particularly glaring issues that have become rather apparent. The first is that casual audiences won't care about all these story details—which, to be fair, is not a problem that is exclusive to any game—or worse yet, that they will get lost because there is just too much information that they have to process. This was a real risk for 343 during their attempt to sprinkle some lore from the books into Halo 4, especially when you consider how many Halo books were released by then, to say nothing of how convoluted all of the Forerunner mumbo-jumbo must've seemed to anyone who didn't read the books.
The second, and perhaps more mildly annoying issue, is that even with the introduction of all these new characters and locations and whatnot, almost everything that happens in Halo's extended universe happens as if it were being presented through the eyes of someone who played through the other Halo games. This is actually a fairly inconsequential matter in Halo Wars 2, if you disregard the fact that the main characters of the game have been asleep and drifting through the infinite emptiness of space for almost three decades, which is when the events of the other Halo games took place. It is hard to say, but one can probably safely assume that people who were unexpectedly teleported to a very specific location in space which just so happens to be a place that was literally designed for the purpose of manufacturing massive weapons of galactic destruction would likely be much less nonchalant about their situation, and that's just the tip of the iceberg.
But for all of its flaws, the underlying story behind the Halo extended universe is a fascinating subject that has a lot of potential. Could it be presented in a better way? Without a doubt. It may not lead to your average Halo player purchasing every Halo book in existence, but at the very least it would allow for a more airtight and compelling narrative. As it stands now, though, there is no real reason not to do some "light research" into the Halo universe if you have even a passing interest in science fiction. There are no shortage of cases where some things make no sense, even in the context of the universe (seriously, how does Anders know how to do everything seemingly by herself in Halo Wars 2?), but such things can be overlooked for the sake of delving into the interesting story of one of the most influential games of our time.