[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/general_8.png]]
[[caption-width-right:350:''Glory to the Flora.'']]
Despite the innocent-looking game (or maybe moreso because of it), there's some frightening stuff.

!!Character Storylines
* All Resistance members (safe for Demon Slayer) get the [[SarcasmMode absolute pleasure]] of meeting [[EvilGenius Gelimer.]] He's a MadScientist that [[InvasionOfTheBabySnatchers likes to kidnap young children]], [[{{Brainwash}} brainwash them]], subject them to UnwillingRobotization, and by the end of it, most of them have been turned into [[KillerRobot cyborg soldiers]] at his disposal.
* Ark's storyline, not even before you hit his second job advancement, treats us to a flashback where Ark firsthandedly [[KickTheDog saw the genocide of an innocent species.]] The one afterwards shows the survivors presumably being ''burned alive'' while Albaire and Ark look on, followed by General Limbo showing off his "[[SlasherSmile true form]]", which is the current page image.
!!Quests, Blockbusters, and Events
* The 2016 Masteria Haunted House event for Halloween:
** The [[https://static.wikia.nocookie.net/maplestory/images/8/84/Mob_Sophilia_Doll_Ground.png/revision/latest?cb=20080125184156 Sophilia Doll monsters]] and [[https://static.wikia.nocookie.net/maplestory/images/2/29/Mob_Sophilia_Doll.png/revision/latest?cb=20080125184156 Sophilia Doll-head marionettes]], both which cry like little girls when defeated. [[https://www.youtube.com/watch?v=hiiLGFpEZqI You really have to watch it to feel it.]] It's worse if one knows the story behind the mansion and its people. The dolls are modeled after the daughter of the man who ran the toy-making shop in the mansion (it was noted that these dolls looked creepy enough even before they were possessed). Sophilia was climbing up a chimney and fell to her death, causing her father to lock himself in his factory and eventually starve, and her butler to be overwhelmed by guilt. When the mansion was first released, those that got in could converse with the ghosts of the inhabitants, who were, aside from a few, unaware that they had been dead for what was probably decades. Now imagine that sweet, innocent Sophilia, who just wants her first doll, some candy, and to see her father, then imagine her wailing like the death cries of the dolls.
** FromBadToWorse is practically a theme of the place! Poor Killian, oh yes, poor Killian, stuck roaming the woods which moan in the night, headless and an eternal slave of the Black Magician. THAT was a MoralEventHorizon crossing for the Black Magician, condemning someone to AndIMustScream for eternity.
* The Madhouse Event is one Nightmare Fuel after another. First off, if time runs out, the last thing you see before being kicked out of the dungeon is a glaring blue eye (presumably TheMole Sean's, right before she strikes with a ''skull for a pupil'' and a scream, presumably yours. If you enter a room without a light or take the wrong medicine, you wind up in a room where you find one of your friends being tortured. (Worse, the devices the doctors and orderlies are using on them? Those are ''chairs'' you can get from the Vending Machine if you ever want to see ''your'' character like that.) Not to mention, as you put together Chloe's diary, you start to learn, one bit at a time, just what happened to her; and when compared to Sean's brief diary, found in the epilogue, you find ''her'' point of view, and discover the truth, when pieced together, [[SplitPersonality the truth of the killer's identity]] should come as a shock.
* [[https://static.wikia.nocookie.net/maplestory/images/2/21/Mob_Alloy_Xenoroid_DX.png/revision/latest?cb=20150115035736 The]] [[https://static.wikia.nocookie.net/maplestory/images/6/6a/Mob_Alloy_Xenoroid_EX.png/revision/latest?cb=20150115035738 Xenoroids]] in Black Heaven and the Scrapyard. Those guys just aren't right. (Although, storylines show they're [[DarkIsNotEvil just as capable of sentience and emotion]] as the other robots.) And what's more, it's clear that those are just mechanical [[{{Expy}} expies]] of [[https://static.wikia.nocookie.net/maplestory/images/2/24/NPC_Xenon.png/revision/latest?cb=20170808080558 Xenon]] and [[https://static.wikia.nocookie.net/maplestory/images/8/82/Mob_Beryl.png/revision/latest?cb=20121228155640 Beryl]], which makes them all the more unnerving.
* [[PersonalizedAfterlife The Afterlands.]] They may be the world that you go to after "dying". If that's so, then it means that the children in the Afterlands ''died''. In fact, all the characters in the Afterlands give off this vibe, since it is never explained how they originally arrived, and they don't even mind that they may be dead, despite there being a possible way out. Heck, even after the storyline is done, you don't know anything about what that world really is, and given how the old man who you help in the beginning wakes you up whenever you leave the Afterlands, it may be [[AllJustADream just a really bizarre dream]] (although the ending puts that into question).
* Mechanical Hearts- first we learn early on that Aspire's new androids, which are being sold as consumer goods, have emotions rather than merely programmed responses. This doesn't stop Aspire researchers from tormenting them for testing purposes. Hundreds of them exist in constant pain for scientific research. Upon helping expose what's happening and shutting down Aspire, the mainframe develops an AI, goes insane and wants to punish all of humanity for the torment of the Wondroids. Robots left in the facility are activated, any human workers trapped inside were torn apart, bonded with machine parts and turned into security drones(with the heavy implication that they are fully aware yet can't do anything). Even after the AI is defeated, Aspire's CEO has her body destroyed and mind trapped in a computer that isn't connected to anything, and a former researcher is severely injured, requiring Wondroid parts to fix the damage to his body. The ending also implies further chapters may be added.

!!Bosses, Monsters, and Areas
* The Black Mage himself, who encases the heroes who fought him in ice, and in the future [[TheBadGuyWins manages to corrupt Empress Cygnus and her knights and conquer all of Maple World in a bad future.]] He also is responsible for causing a cataclysm that dramatically changed Victoria Island once the Black Wings managed to remove his seal.
* The boss Alishar. [[https://static.wikia.nocookie.net/maplestory/images/7/77/Mob_Alishar.png/revision/latest?cb=20110901131115 At first glance]], it's already scary-looking: a mutant whale with glowing eyes, huge teeth, prominent nipples, and tiny legs. Then it flips over and attacks. ''[[https://www.youtube.com/watch?v=7NaMlEvDzMQ Those "nipples" are eyes to a demonic beast.]]''
** From Alishar's Death Magic in iTCG: "His clock knows the hour of your death."
* The Soul Teddy monsters. The first one, [[https://static.wikia.nocookie.net/maplestory/images/6/69/Mob_Soul_Teddy.png/revision/latest?cb=20080126050721 Soul Teddy]], doesn't seem so bad. The [[https://static.wikia.nocookie.net/maplestory/images/1/12/Mob_Master_Soul_Teddy.png/revision/latest?cb=20080126054854 Master Soul Teddy]] is still more cute than scary. Then you run into [[https://static.wikia.nocookie.net/maplestory/images/2/21/Mob_Death_Teddy.png/revision/latest?cb=20080126010307 Death Teddy]] and [[https://static.wikia.nocookie.net/maplestory/images/c/cf/Mob_Master_Death_Teddy.png/revision/latest?cb=20080126014054 Master Death Teddy]]. Their corruption of a teddy bear as a comfort object is what hits hardest.
* Some of the tree trunk interiors in the Ellinia woods simply look cavernous with a lot of tree bark to jump on. Some of the trunk interiors in the higher parts of the woods, however, look like something out of an alien horror film.
* Some regular monsters, like Dreamy Ghosts and Eyes of Time look kind of cute, until they actually attack you and put on a rather horrific GameFace.
* When killed, Octopus monsters fall down [[FamilyUnfriendlyViolence while their skin rips open exposing their flesh as their eyeballs drop from their orbits]]. This being the most disturbing animation in the game.
* The SpikesOfDoom throughout the game can range anywhere from small and annoying to large and terrifying-looking.
* Previously in the Chinese and Taiwanese versions, you could find [[https://static.wikia.nocookie.net/maplestory/images/5/5b/Mob_Blue_Kid_Mannequin.png/revision/latest?cb=20130619155904 these]] [[https://static.wikia.nocookie.net/maplestory/images/4/42/Mob_Purple_Female_Mannequin.png/revision/latest?cb=20130619155911 mannequin]] [[https://static.wikia.nocookie.net/maplestory/images/6/6c/Mob_Silver_Male_Mannequin.png/revision/latest?cb=20130619155919 monsters]] in the Kerning Square, and they're... kind of unsettling.