* Why did Durandal turn down godhood? He doesn't want to be alone. Sure, he'd be a god, powerful enough to reshape his new universe, and able to do anything, but he would be alone. Also, he would know everything. He wants to know everything, but once he reaches that goal, he'd have no purpose. He would be lonely and unable to learn. That is a FateWorseThanDeath.
* In ''Infinity'', the W'rkncacnter affects all the timelines. [[spoiler: By preventing its release in one timeline, the player did it for all of them.]]
* [[spoiler:''Infinity'', such as the chapters after the Prologue being: '''D'''espair, '''R'''age, and '''E'''nvy, and the final level being '''A'''ye '''M'''ak '''S'''icur.]]
* The amount of detail that went into the plot sometimes is just staggering. [[http://marathon.bungie.org/story/hangbrainchip.html Here (massive spoilers)]] is a good example of something that does not make the slightest bit of sense when you first play Infinity, but players have puzzled out what the developers were thinking when they developed the game and come up with explanations that make perfect sense. This is one of only dozens of examples, as well.
* You can ''dual-wield shotguns''--a feat that, in real life, would snap your arms like twigs [[spoiler: unless you were a battleroid]].
* In Infinity and in Durandal we find out that the W'rkncacnter are not threatening when trapped in their prisons, however all of their prisons (blackholes, storms, stars, ect.) are temporary at best, meaning they would eventually get out, and having no way to kill them adds to the fear factor.
* This one goes hand in hand with AndIMustScream. It turns out that ''VideoGame/PathwaysIntoDarkness'' and ''Marathon'' are in the same universe, and in that universe, when you die you are forever stuck in your body for the rest of eternity, or it is implied.
* The cyborg tanks in the second and third games are confirmed by WordOfGod to be created from captured humans. When one thinks about the fact that the Pfhor are slavers and have thousands of years of history, one considers that they have probably done something similar to all of the races they've enslaved. There is also a theory that the "assimilated [=BoBs=]" - which look human, run up to you, and explode - might actually be captured humans as well, but the game says they're artificial constructs (however, whether this is actually the case is open to interpretation, as the games flip-flop a bit on this point). Either way they're a pretty strong source of FridgeHorror as well.
* Tycho's personality notably does a complete one-eighty between the first game (where he demands justice for the colonists that Durandal's actions have endangered) and the next two (where he is...much less concerned with that, among other things). Obviously, going Rampant had a lot to do with that, but in one of his few terminals in M1, he informs Durandal that the S'pht rebuilt him in Durandal's image. Tycho has this habit of trying too hard to be poetic, but assuming that he was speaking literally here, well--as [[http://forums.bungie.org/story/?noframes;read=69216 was asked]] in this longer discussion on his character: to what extent is Tycho still himself? How much of him was remodeled/discarded to emulate Durandal in his unstable Anger stage, and how much is a complete mess from incompatibility?