- Let's be honest: anytime the Ominous Music Box Tune starts to play—or worse, when a normal, casual song gets cut off by it—something unnerving is about to be revealed. It becomes Nightmare Retardant in the April Fools DLC, however.
- Any time Unknown appears when you least expect it gives a little Jump Scare. The Ominous Music Box Tune makes it worse.
- The bad end of the prologue reveals that Unknown had been standing there the whole time as the reader entered the apartment. If you say you don't see the lock twice Unknown comes out of nowhere and decides to take you with him. The only reason he doesn't kill you is because you're "cute."
- Not just that, but he can go inside the apartment at any time too, as evidenced with some of the bad relationship endings (Zen's and both of Jaehee's). It's quite jarring to go back into the apartment like normal, and then seeing him come out of nowhere.
- The Casual Story's bad ending is another frightening event, maybe overlapping with Fridge Horror. Yoosung becoming aware of how he is just programmed is one thing, but imagine the scene from Zen's and Jaehee's points of view. The youngest member of your group, whom you consider a friend, suddenly starts talking about how he's a robot, and how other group members will probably discard him when they find out what he's saying. And he's completely serious, too. Oh, and when you get to his place to talk to him and maybe ask him to see a psychologist, he's gone without a trace.
- In the Deep Story's 5th Day bad ending, V is seen loitering around Mint Eye's castle and is then caught by Unknown, who kidnaps him and calls Seven. Seven decides you're better off not being involved with the RFA and deletes your account, leaving their fates unknown.
- All of Yoosung's bad story endings are scary, since his backstory is closely tied to Rika and, by proxy, Mint Eye.
- In Yoosung's first bad story ending, he goes further than to just believe Rika and the player are similar, and even refers to the player once as Rika's reincarnation. His possessive streak goes up to eleven as he forbids her to speak to anyone else but him, and eventually decides to go to Rika's apartment himself (despite V's orders) to "save her." There, he says repeatedly that he loves her while a creepy music box plays in the background. And then they both blow up because by entering Rika's apartment Yoosung triggered the bomb and didn't even pay any attention to it. Charming.
- In his second bad story ending, which you get if you encourage him to stop trusting V and the RFA, he'll ask you to meet him personally at a park at nighttime, where you both encounter Unknown (who, by the way, is speaking with his mask on). Unknown tricks Yoosung into believing him by hinting that he was bribed into keeping an autopsy (on Rika's body, Yoosung assumes) he had performed a secret. At this point, Yoosung breaks his cell phone to earn his "trust" and you get in his car... and once you realize something's wrong, you're already on your way to Mint Eye. Stranger danger, anyone?
- In his third bad story ending, which you get if you convince Yoosung to sacrifice himself for you, Yoosung doesn't come back from Seven's mission and is forced to be Unknown's prisoner in exchange for the safety of the RFA. The poor boy is tortured every minute of every day, and it doubles as a Tear Jerker when you hear Yoosung's broken voice and his dying will to keep everyone safe.
- Close to the end of Zen's route, the player gets to hear a conversation between two people about how one wouldn't mind destroying and torturing RFA, and that the player, will be taken to the speaker's place. After the next chat, Unknown appears in the player's appartment, talking about how they'll take the player with them, and threatening to use force if she resists. During that scene, a pretty unsettling melody like one from a music box plays in the background. And if that wasn't enough, the two chats are between 11 PM and 1 AM, so if they're played right after they're unlocked, it'll be the middle of the night. Granted, it's revealed that at least the kidnapping was only a dream of Zen's, but it's scary nonetheless. Doubles as in-universe Nightmare Fuel, since Zen calls the player right afterwards, terrified that something may have happened.
- Shortly before that, on the 8th Day, the very first chat of the day (just after midnight) starts out quite buggy and similar to the first chat the player had with Unknown. There will be a few incomprehensible messages, and then one saying "traitor". Right afterwards, the weird part disappears and 707 enters as if everything was normal, claiming it was probably just a bug. Seven's presence right afterwards might dissolve the Nightmare Fuel a bit with his positive attitude... until the Visual Novel part, where he notices that Unknown got into the chat. His reaction being "Gaah!" doesn't sound too good...
- In the last conversation of 4th Day in the Deep Story Mode before the game branches off, after Seven leaves the chatroom, instead of the game letting you save and exit like you normally would... an unknown person starts talking to you. The first few messages are incomprehensible, but the last words you see before the save pops up are: "I am / going to / corrupt you".
- Even worse? The hacker never shows that they've entered chat. This could imply that they could've been in the chatroom with you, Seven, and V the entire time. And since it's implied that the other members can read past conversations they weren't part of, it makes one wonder... if any of them could see the mysterious messages or if it was just you.
- If you've already played through one route, the bomb is constant Paranoia Fuel. You know it's there. You're pretty sure it will become a plot point later on. But you don't know when, and you don't know what exactly will happen. And characters making jokes about "explosive" news or something similar doesn't really help.
- Also, no matter which route you are on, Unknown has the switch to the bomb. That means he could activate it whenever he feels like it. What makes it even more frightening is that he doesn't care if he gets caught in the explosion as well.
- The premise of Mint Eye. Rika wanted a world without any pain and just endless happiness which she tries to achieve through brainwashing and torture. No wonder V called it a dictatorship...
- There's also what the brainwashing did to Saeran. He was originally a sweet young boy who adored his twin brother, and just wanted to escape his abusive mother. Some time after Seven left to join the agency, Rika kidnapped Saeran and pumped him full of drugs, all while telling the terrified Saeran that Seven left because he secretly resented looking after him. This caused Saeran to develop a hatred towards Seven while believing that Rika "saved" him, which led to him becoming the insane, homicidal Unknown that opposes the RFA members and wants them dead.
- Rika. From brainwashing Saeran to blinding and abusing V, she's a truly disturbing character. She's been hurting and misleading V for so long that he thinks he deserves the abuse.
- Unlike all the other After Endings, Seven's After Ending is more of a Downer Ending. First, there's a Hope Spot where it shows that Saeran has officially escaped from Mint Eye and reconciled with Seven, even befriending the other RFA members. And then, right when you think a Heartwarming Moment is about to appear... there's a Cruel Twist Ending where it turns out that it was All Just a Dream, which is even more chilling when the Ominous Music Box Tune plays.
- Speaking of Hope Spot, on the 10th Day of Seven's route, some players will go in on the game branch thinking everything is okay, and that Saeran will be saved. If you picked the wrong choices? Surprise! You're treated to a Hope Spot where Saeran says he believes you, and everything seems okay... until he leads you into a trap with the intentions to keep Seven as his prisoner forever. Congratulations on the ending!
- Seven's second bad ending on the 10th Day (Bad Relationship Ending 2) ends in Saeran having a mental breakdown and shooting Seven to death in front of your eyes. It doubles as a Tear Jerker in that before it happens, Seven is trying to comfort you and also counts as Fridge Horror in the implication that you're killed along with him since Saeran mistakes you for his mother.
- Jumin's infamous Bad Ending can be straight up terrifying, especially for people who went through Domestic Abuse. If you encourage his possessive qualities, he goes overboard and traps you in his house. He goes on and on about how you're most "precious" to him and how he should be the only one allowed to have you and how he wants to "possess" you. He then proceeds to regulate everything from your dress to your room to your food. And the kicker? He puts a micro GPS in your shoe so that he can track your every movement! How many fans managed to find this ending "sexy" is anyone's guess.
- Jumin's possessiveness doesn't end there; in his Bad Relationship Ending 2, his possessiveness goes so out of hand that the only option is being Driven to Suicide.
- The Jump Scare in the commercial (from 0:52 to 0:55) is rather unexpected and is frightening because of how it came out of nowhere. During the last 4 seconds of the advertisement, Evil Laughter ensues.
- The first chat on Christmas Day in the Christmas DLC begins with Unknown hacking the messenger to deliver a message that seems to be "Merry Christmas." It looks pretty harmless, but he texts you after the 12 AM chat room closes, and you have the option to reply. In the original game, he never responds to your texts, but here, you do get a rather unsettling reply.Unknown: I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge I'll get my revenge
- He continues to contact you throughout the day with unnerving comments. Around 5 or 6 PM, he calls! And manages to make "We Wish You A Merry Christmas" creepy as he sings it in a painful-sounding stage whisper, breaking into unhinged laughter at the end.
- If you respond to all of his texts saying that you want to meet him, you'll get a bad ending where he shows up in the apartment when you get home from the party and kidnaps you while he becomes a Knight Templar about establishing a Christmas that's inclusive and interpreting you shaking in fear as love. It's obviously not good news, since your disappearance causes everyone to go into panic while you're stuck entertaining Unknown forever.
- In V's route, there's a lovely scene of Ray force-feeding V the drugs that Rika uses to brainwash her victims. V's cries and coughs of agony are already difficult to listen to, but there's also the implication that Ray's holding back on him - Ray constantly talks about how the "bad him" (presumably his Saeran/Unknown personality) is itching to come out to torture and kill V - and he almost does.
- If you call V after that, you'll hear V panting and coughing, quite obviously in huge pain, while Ray demands him to tell you not to worry. Instead V tries to apologize for not saving you, which angers Ray. After that V goes quiet and Ray, sounding like he's on the verge of a mental breakdown, quietly says to himself that since V's still breathing everything's fine. He then tells you to listen to the savior and that he has something to take care of and hangs up. The whole thing couldn't possibly be more horrifying.
- When Ray hacks into the messenger on the 6th Day of V's route, you get a text message from him through V's account, which has also been hacked. Yoosung mentions that he can't call Jumin. Note that if you try calling Jumin right after the conversation, you'll notice that you can't. All your call logs with Jumin (except for the ones where he actually picks up) have also been deleted.
- On the 2nd Day of V's route you have a chat, supposedly with V, but when you log in you notice that the background is the same as when you talk with Ray. "V" greets you and says several things that, from him, sound quite creepy, like calling the RFA members "stupidly naive" and warning you not to trust them and "himself", since "he" is "more hypocritical than you'd think". Then it turns out it was Ray all along. And while that was pretty obvious from the start, it's still highly disturbing that Ray hates V so much that he decided to hack his account, as well as the fact that he could do this at all.
- On the 7th Day of V's route, Ray begs you to stay. When he logs off, the screen suddenly breaks. By the next day, after Seven saves you and V, he force shuts down the messenger in attempt to save the RFA and salvage the app, but by then, Ray has completely taken over. That's right, now the messenger glitches and the coding that shows up is now red. Cracks are all over the screen, and you hear mostly static when you call anyone besides Seven, V, or Ray. Even worse, Ray suggests registering Rika as a user, despite your protests. Not only does he do it after the following conversation, but he also deletes Jumin, Zen, Yoosung, and Jaehee's profiles, so they can no longer see what's going on. Once Rika is registered onto the messenger, she starts calling you! The messenger is no longer a safe place with these changes.
- In Ray's route, one CG has Ray being forced to drink the Elixir by Rika and far later, we get to know the process of how Saeran was brainwashed into becoming Unknown. The process is downright horrifying.
- Also in Ray's route, after Rika "cleanses" him and he snaps, Saeran spends a couple of days abusing MC in just about every possible way. He locks her in her room, starves her, deprives her of all human contact except for himself, constantly demeans her so he can feel stronger than someone, makes disturbing comments while touching her without her consent, and constantly threatens her with torture and death. To some fans, it's Nightmare Fuel that you have to forgive him to get the good ending.
Nightmare Fuel / Mystic Messenger
If you thought this game was about arranging parties, you are completely wrong. There are plenty of chilling moments in this game as the days go by.