These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation: A LOT of dispute remains over whether the Firstborn is an inhuman, malicious monster or a tragic, abused being remains. Certainly, it seems to be rather eager to break into reality and destroy the world as we know it and its killing of Cole and Jones is recognized by all to be quite vile, but considering that it is suffering from an eternity of Parental Abandonment in which the parent is God and the Abandonment consisted of being kicked of of REALITY ITSELF (and which we don't exactly know if it is even possible for it to return to it without screwing everything up), after which God chose to create new, more favored children... yeah, let's just say it has valid issues. Of course, the converse is that the Firstborn- having great power but virtually no restraint or responsibility- was recognized by God to be fundamentally unfit for reality and only confirmed that evaluation by promptly trying to destroy said reality due to the equivalent of a temper tantrum and whose malignant nature was confirmed by the needless slaughter of Cole and Jones... Let's just say this is prime ground for an Internet Backdraft amongst fans.
In the Dummied Out Alternate Ending, the Firstborn turns out to be neither good nor evil. The High Priestess of Ur, Ereshkigall (who is also the True Final Boss in this ending), enslaved the Firstborn to use its power herself. The Firstborn was powerless to resist Ereshkigall, for it was lacking a soul. When Ross gives his disembodied soul to the Firstborn, it is finally able to destroy the vile priestess.
Awesome Music: Pretty much the entire soundtrack, particularly the boss battle/regular battle themes. Especially the ones that involve epic, creepy choirs.
Demonic Spiders: The Exploding Cultists count - and they're among the most common enemies in the game. Lichthammer's Flamethrower and Machinegunner soldiers also count.
Game Breaker: While every squad member's abilities can be abused up to some level, Jones and Rawlings are the worst offenders. Jones is capable of casting multiple Blood Wards and draining enemy creature's health in the process by using his Astral Projection, while Rawlings gains the ability to heal fallen comrades while standing at the opposite end of the level, as long as he's player controlled. The latter is especially imbalanced, since it enables the player to win most battles without firing a single shot themselves, simply by pressing Rawling's healing-key whenever that little skull-icon appears on the screen, all the while standing in a remote corner out of harm's way.
Goddamned Bats: The Flying Cultists, and the Child Crusaders. The Exploding Cultists vary between this and premium grade Demonic Spiders depending on whether or not you plan on getting the achievements.
Fortunately, using Church's Blood Ward on the Exploding Cultists, before running up to them and giving them a single slash with her sword can be a very effective technique to use against them. Just make sure you run after doing it.
The flies, as well - even though they are a plot device and are usually around to take away the bodies of deceased enemies, it is possible to be swarmed and attacked by them during the fights with Lichthammer and the duel fight against Nanna and Utu (all three have the ability to control the flies), which can be quite disorienting.
Hell Is That Noise: The Child Crusaders' creepy, childish giggles, heard shortly before they attack the squad. The sound of their shrieking is also pretty horrific.
Narm: The story and characters might otherwise be interesting, but it's difficult not to wince at some of the one-liners tossed out during combat.
Player Punch: Close to the end of the game, the deaths of Cole and Jones at the hands of the Firstborn are incredibly shocking, sudden, and cruel. Also, the death of Muriel Green near the beginning of the game counts, especially since it follows a rather touching scene involving her and Rawlings, and some character development.