Omori/Nightmare Fuel

General

 * You can look at a mirror of the friend group in Headspace up to four times. Most of the times, the reflections is normal. The fourth time, you see a Eyeless Face quartet starting back at you with Slasher Smiles.
 * The moment when you realize there is nothing fantastic about this game. All the horrors -- grief turning you into a monster, neglectful parents, self-harm, hallucinations that skew your vision of reality, - are actually real, and what seemed magical was part of a dream world.
 * Sunny's mental health has deteriorated so badly in both routes that he has forgotten to eat, change clothes, or do little things such as brush his teeth. Heck, Aubrey has to remind him that Mari died four years ago because he doesn't want to believe the truth.
 * There are two ways for Omori to exit Whitespace: one is if the door opens to Headspace. The other is if he grabs his knife and stabs himself when the door isn't there. Omori calmly does this when you click "Stab," and you hear a squishing sound. You cannot avoid this.
 * The Reveal that Omori is not the hero of the story. No, he's the villain and the creator of Headspace. He manufactured the Basil quest for two purposes: to keep Dream-Basil from revealing the truth to Sunny, and to make the dreamworld more appealing then reality. And why? Because Sunny didnt want to face the reality of what happened to Mari.

First Segment

 * Seems like it will be a cutesy game, after you help Omori and his friend group rescue Basil from a random monster. Then when they gather in Basil's house, Basil picks up a photo he dropped. He says with confusion that he didn't take this photo, only to go Oh Crap. Then he stammers, "Mari, she's-" before we see the photo flashing and Omori back in Whitespace. We see the photo later during the Truth Segment: it's a broken violin.
 * Sunny wakes up, hungry, and wanders downstairs. Rather, he tries to do that, but a monster called Something appears on the stairs. You can't hurt Something, but it can do damage to you. The only way to get past Something is to listen to someone encouraging you to breathe, and activate the skill Calm Down. All the while, Something stares at you with utter hatred.
 * After getting sick from leftover steak, Sunny hears pounding on the door. You can ignore it and go to bed, or answer the door. Mari's out there, saying she forgot her housekeys. She wants Sunny to let her inside. If you choose to open the door, something comes through the door that is definitely not Mari. It's blue and has an elongated neck. Most players run for their lives and return to bed.

Main Route

 * You activate this route by opening the front door when Kel knocks in the morning. While going to get a present for Hero, who is returning from college, you notice someone familiar: Aubrey. But her hair is pink, she's holding a bat, and she's bullying Basil in the real-world. Kel tells her to knock it off, and she challenges him and Sunny to a fight. Yes, she will use the bat. Sunny can slash her with his steak-knife, which causes her to bleed and leave immediately. Kel gives Sunny a What the Hell, Hero? and confiscates the knife, saying that it's dangerous to carry that around.
 * Humphrey the Whale doesn't seem that bad. Sure, he swallows you, but he says it's so you can get another hint. The friendship group is unaware that Humphrey was using them to ensure that the Slime Girls feed him. When they and Sweetheart fail to do that, Humphrey takes care of them by swallowing them. Then he turns on the friendship group, threatening to eat them in turn.
 * Blackspace
 * You access this after completing the Hangman puzzle: "Welcome to Blackspace." When you take the friendship group to Basil's house, and by then the group has been losing their memories of Basil, there's a giant tentacled hole. Omori approaches it alone, and the narration asks, "Do you want to jump?" Saying yes is what leads to you finding Mari in a coffin, who quickly turns into a monster reaching out to you before vanishing.
 * One mercy of this particular space is you can skip all the rooms and go straight to the red door. Most players don't, showing how fascinating the rabbit hole has become.
 * A corrupted arrangement of "Peter Gynt" plays when you enter a world that looks like deranged Windows Paint drawings.
 * There's one room where we see the friend group swimming in individualized pools of lava. Copies of them also trapped in stone, and the faces look conscious.
 * The Truth
 * Sunny ends up in Whitespace. Omori has nothing to say to him, and there is only one thing to do: break the black lightbulb. After you do, you face Something again, in all three forms. This time, Sunny does not flinch, and learns a new skill: Overcome. It shows Something's true form: Mari's body hanging in the wind. It's a bit of a Wham Shot that foreshadows how rough this will get. Sunny can only face it, and pick up a white lightbulb.
 * Dream-Basil finally catches a break: he thanks Sunny, not Omori, for coming to find him in front of a hollow tree. After giving Sunny his photo album, however, Basil warns him that the truth of that day will be hard to live with, so please forgive him. After you go into the tree, the scene changes to Sunny's mother watching TV listlessly and talking to Sunny, saying she can't lose him after losing Mari, "my only daughter". Yeah, this is going to be rough.
 * The next room is a giant hospital ward. Nearly every bed has people in it connected to either life support or body bags. You have to collect photos from the beds, the more you do that, the more patients disappear. Then you reach the last person: "This patient isn't breathing." Only then can you progress through a red window.
 * The more that Sunny walks through the different rooms, the bloodier that he becomes. By the end, he's basically a reddened lich.
 * The Reveal, all of it which you can get by data-mining the photos that you collect: Mari didn't die by suicide. She and Sunny got into a fight the day of their sibling recital; Sunny heard her scoffing at his mistakes, and in a fit of fury he tossed his violin down the stairs. Mari went to confront him, because the friend group had pooled all their money for months to buy the violin. Sunny, in a fugue state, tried to walk away as he was unable to speak in his rage. Mari, however, stepped in front of him on top of the stairs and said she wasn't done with him. Sunny lashed out in rage...and Mari fell. Her bad knee probably didn't help either. She collapsed on top of his violin and lay still, at an odd angle. Sunny, coming back to his senses, ran downstairs and begged her Please Wake Up, saying that he was sorry. Not knowing better, because first rule of head injuries is do not move the person and instead dial emergency services for help, Sunny dragged her upstairs and put her to bed, convincing himself this is a bad dream. You can see a Dead Hand Shot in the photo where Sunny collapses by her bed, showing she did die for real.
 * How does Basil play into this? Basil happened to come in and witness the fight, as well as Sunny pushing Mari down the stairs. Unwilling to believe what he saw, Basil freezes until he goes up and sees that Mari's hand is limp, and Sunny is sobbing Tears of Remorse. Basil orders Sunny to take Mari outside, and they grab a jump-rope, fashion it into a noose, and string her up the tree. They positioned the toybox to make it look like she kicked it away. When they turned to look back, rigor mortis had set in and one of Mari's eyes opened to glare at them. This ended up becoming their Somethings. Even Basil is not sure why he thought this was a good idea if you stop him from committing suicide, if you decide to "save" him.
 * How does Basil play into this? Basil happened to come in and witness the fight, as well as Sunny pushing Mari down the stairs. Unwilling to believe what he saw, Basil freezes until he goes up and sees that Mari's hand is limp, and Sunny is sobbing Tears of Remorse. Basil orders Sunny to take Mari outside, and they grab a jump-rope, fashion it into a noose, and string her up the tree. They positioned the toybox to make it look like she kicked it away. When they turned to look back, rigor mortis had set in and one of Mari's eyes opened to glare at them. This ended up becoming their Somethings. Even Basil is not sure why he thought this was a good idea if you stop him from committing suicide, if you decide to "save" him.

Hikikomori Route

 * The fact that this route exists, and Sunny never faces the truth. (You trigger this route by not opening the front door when Kel knocks.) Sunny allows Omori to take over him in the real world, and live permanently in denial. It's also implied that because you didn't interfere, Basil commits suicide independent of your actions.
 * There is an Eldritch Abomination named Abbi who doesn't have a real-life counterpart. It's implied Omori locked her away because she didn't want to play by the script.
 * Sweetheart has skeletons in her dungeon in this iteration. One has Aubrey's signature bow. Welp...
 * To "save" Sunny from Something, Omori takes over him, and this time it isn't a fight. Sunny surrenders completely to Omori, meaning that he has completely succumbed to the dreamworld fantasy.
 * Blackspace 2
 * Omori either has a memory or a projection, of Sunny's father cutting down the tree where Mari allegedly died by suicide and disowning him. The worst part is we don't know if it's even real or not.