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.
Demonic Spiders: Ak'ab: Giant moth-monsters that, while they do little damage, have lots of health, move around a lot during the fight (increasing the odds you bump into more of 'em), spawn thick on the ground, patrol over wide areas, constantly knock you down and generally combine all the worst parts of every MMO enemy into one.
Ensemble Dark Horse: Dame Julia Beatrix Tyburn. This old lady is somewhat uptight, but it's hard to not laugh of the stuff she says, and how she says it. Even more, she does seem to have some respect for people even though they are not from some family of "blood", like the traditions of the Templars would rather have in their ranks.
Gameplay Derailment: The '/reset' command was intended to allow players to by-pass bugged missions and instances by respawning them. Instead, it's been commandeered for 'suicide teleportation': fast-travelling across the area by dying in one place, and respawning at the Anima Well closest to where they intend to go.
Iron Woobie: Most of the civilians in Solomon Island and Transylvania. They've had to deal with attacks from zombies, Draugr, vampires, ghouls, werewolves, and all manner of other horrors lurching out of the darkness to kill them, but they're still weathering the storm. Sheriff Bannerman of Kingsmouth is positively upbeat about the whole situation.
"The Vanishing of Tyler Freeborn." It turns out that the Fog is an airborne strain of the Filth; anybody who breathed it in is infected- meaning that the entire surviving population of Solomon Island is effectively doomed, and nothing you do to help them will change that. Just to drive the point home, the same mission also forces you to fight and kill Filth-Infected replicas of Helen Bannerman, Deputy Andy (including pet kittens), Scrapyard Edgar, Headmaster Montag... and all of them carry on reciting lines appropriate to their characters as they try to kill you.
Meeting Sarah in Tokyo can be one of these. In the Tokyo flashback sequence, you relive her memory of the damage control team's response to the Tokyo incident. In the original sequence, it is implied that you are simply experiencing a memory, or going back mentally in time to live the experience. It turns out in Tokyo that Sarah relives the memory every time a player character does, and has almost been driven mad by reliving the memory over and over.
Stoic Woobie: Hayden Montag. As a child, his studies in magic accidentally killed his mother and eleven other innocent bystanders- crimes for which Hayden turned himself in. As an adult, he's headmaster of Innsmouth Academy... and by the time you meet him, most of his faculty and students have been murdered by the monsters that have invaded Solomon Island, leaving him and two others to keep vigil over a school overrun with monsters. And, beyond a few absent-minded mutterings, he weathers the storm calmly and analytically.
That One Sidequest: There are two Investigation missions that require the player to transcribe Morse code. The first one is in audio form, and is played at normal speed, making it almost impossible for someone not educated in it to follow.note There is accompanying video, but it plays too fast to be useful as a visual aid. The second one is in blinking light form, and while slower than the first one, still takes quite a bit of trial and error to transcribe correctly, and you also have to figure out for yourself that you're looking at a Morse Code sequence in the first place.
Marianne Chen; last surviving member of a CDC team sent to investigate the emergence of the Filth in Solomon Island, she's had to watch the rest of the team die horribly- either from the arrival of the Fog or direct exposure to the Filth. Effectively abandoned by her superiors and left all alone in a badly-defended base camp overlooking the swamp where her teammates died, she now lives in daily terror of something crawling up the hill and murdering her in her sleep- or being infected, hence the reason why she hasn't taken off her Hazmat suit since the Fog first swept in. The player is literally the only human contact she's had in the last few weeks, and it really shows in her dialogue.
Carter, Innsmouth Academy's star pupil. Having possessed magical powers since birth, she's ended up accidentally destroying most of the houses she's lived in over the years, forcing her parents to move near-constantly just to avoid attention from the police; eventually, they had to hand her over to the Innsmouth Faculty at age twelve, if only because they were more capable of helping her control her abilities. As such, she's the poster child for I Just Want to Be Normal... and it's only gotten worse since she's had to deal with the arrival of the Fog.
Uncanny Valley: The intro for a Dragon character has been criticized for running right into this during the blowjob scene, though many still find it effective.