Nightmare Fuel / Kingdom Hearts I

The image on the right depicts some ghostly, ethereal place in the midst of an abyss of total darkness.

And that's just the tutorial level.
  • In the topmost room of Hollow Bastion, the Princesses of Hearts' lifeless bodies are put out on display in crystal containers in the wall like trophies. The game never fully addresses how or why they're in there, but it's implied that some of them have been kept this way for years. With Birth by Sleep later confirming that at least Aurora has been in there for a decade.
  • After his friends vanish, Winnie the Pooh starts wondering how he can "say goodbye to Pooh" when he disappears too. It comes off as a metaphor for death, which is rather disturbing given the source.
  • The minute Sora enters the Second District of Traverse Town, he watches as some guy fades away with a horrified grimace on his face after his heart is freed from his body. Said heart then immediately turns into a Soldier Heartless.
    • The manga has another interpretation of this scene. A Soldier Heartless rips out the heart from a woman (who's implied to be a prostitute) while she's flirting with Sora. Then the Soldier crushes the heart within his claws.
  • On the night Destiny Island is destroyed, Sora sneaks outside only to find a storm, invulnerable Heartless devouring the whole world and Riku being swallowed by darkness. Even after he obtains a Keyblade capable of destroying the Heartless and defeats the giant being of darkness that towers over his islands, he's blown away as the world gets destroyed.
    • Kairi's Dull Eyes of Unhappiness coupled with Creepy Monotone when she appears in this sequence makes it feel even more like some kind of nightmare. All she can say is "Sora..." before wind blows her away like a ghost, she fades through Sora, and disappears.
  • One part of the final fight with Ansem has players fighting in almost complete darkness.
    • The final boss itself can be best described as some kind of organic ship, connected to a giant-sized version of Ansem by thick, fleshy cords that may or may not be its entrails. Despite Ansem controlling it, said ship also sports a Nightmare Face of its own.
  • Pinocchio's world is represented as Monstro. The inside of the whale is basically a Womb Level, and everytime it's accessed, the Gummi Ship doesn't land. It gets eaten whole.
    • Not to mention that when it happens, you first see the Space Whale "swimming" on its own, then it spots you and swims towards you, and finally opens its mouth. It gets worse when you see everything from behind the Gummi Ship, and therefore you get to see Monstro's mouth as it covers the entire screen. Combine that with the final Fade to Black and what you get... isn't a pretty image.
    • You can travel from Monstro's bowels to his mouth in one passage. Cheers for that image, Square Enix.
  • Dying can be rather startling. When the HP bar reaches zero, several things happen in rapid succession — Sora groans, the camera zooms in and circles around him, the screen fades to white, and the Game Over screen appears. In future games, it's slowed down, which makes it come as less of a shock.
    • In the Game Over screen itself, Sora is dead, floating limp in complete darkness, with his heart floating outside of him.
  • Xemnas' Early-Bird Cameo in Final Mix/1.5 Remix as a Bonus Boss is even more ominous than his proper Boss Battle in the second game. Watch it here. The way he speaks, without voice and causing his words to flicker and distort; the way he phases through things and flickers, as though literally out-of-sync with reality; and the way the game refers to him merely as "The Unknown"/"He Who Does Not Exist", plus his incredibly eerie boss theme all combine to make it probably the most haunting moment in the entire game.
    • Made even worse by the fight itself, where he has a penchant for lightning spells and possesses ludicrously agile attacks, jumping around like a deranged Sith Lord.
    • Xemnas's electric shock attack is nightmarish in its own way, but it becomes worse in Kingdom Hearts II when he uses it again in an attempt to take Sora's heart.
  • When the shark from The Little Mermaid appears out of nowhere in the haunted ship in Atlantica, it can be quite startling.
  • Sora commits suicide. He does it for the sake of his friends, and it was all that saved Hollow Bastion, but a young boy still picks up a sword and slams it through his chest, entirely on-screen. And unlike most other Keyblades, the one Sora uses actually ends in a point.
  • The battle against Chernabog is equal parts Nightmare Fuel and Crowning Music of Awesome. The guy, as the interstitials of Fantasia outright state, IS Satan — he's a giant black demon, whose face is bigger than Sora is tall, and he's known as one of the most terrifying beings in the Disney canon. His presence is basically the huge sign that says "You're in the heart of evil, and it's only going to get worse even from here."
    • Bald Mountain being the place that houses the entrance to almost the Realm of Darkness itself should say quite a lot about how Chernabog's area earned the name "Evil Grounds".
    • And the best part? There's no warning he's even in the game. If you're playing it for the first time you don't even suspect him showing up this late in the story if at all. But no, he shows up as pretty much the penultimate boss of the game.
    • Chernabog's demise once you defeat him is frightening as well. He roars in pain, throws his arms up, and is suddenly struck by a huge, purple pillar of light that sounds like a very deep, inhuman drone. We just barely get to see his wings flapping helplessly... and then he's gone, Bald Mountain now being empty.
  • End of the World is a terrifying locale. The music, reprised from the tutorial, makes it seem so serene but you know it's the place of nightmares, being the remnants of countless worlds being destroyed by the Heartless. In the Final Dimension, you see pieces of destroyed worlds raining down constantly. It's truly the heart of darkness.
    • According to the shout-out page, parts of the level seem to be inspired by Nowhere. Get that into your head for a second.
    • Even the Gummi ship routes leading up to End of the World are pretty scary. The music starts out optimistic, energetic and fun, though space gradually gets darker in coloration. Then you get on your way to Hollow Bastion. The music becomes pretty dark all of a sudden, and space becomes very dark. It looks like you're driving through a whirlpool to the deepest darkness. Hollow Bastion is on the very brink of said darkness. Then comes the final journey to End of the World. You're flying in an almost completely dark abyss to the source of all evil in the game, with only a wispy, bright (though definitely not encouraging) array of purple light.
    • And let's not forget the fact that it looks EXACTLY like a black hole, which is very fitting considering it's nature.
    • Once you disembark for the first time, you're in the tiny "Gate to the Dark" cave. The name is already spooky enough, but there's no music. No sound besides the spookiest wind. Then you leave and enter the world proper, and as the music starts, you've finally arrived to the endgame.
  • The mysterious final station of the World Terminus, where you enter a pillar of fire to find a mysterious lab with an even more mysterious message:
    Ones born of the heart and darkness, devoid of hearts, ravage all worlds and bring desolation.

    Seize all hearts and consummate the great heart. All hearts to be one, one heart to encompass all.

    Realize the destiny: the realm of Kingdom Hearts. The great darkness sealed within the great heart.

    Progeny of darkness, come back to the eternal darkness. For the heart of light shall unseal the path.

    Seven hearts, one Keyhole, one key to the door. The door of darkness, tied by two keys.

    The door of darkness to seal the light. None shall pass but shadows, returning to the darkness.

    Ones born of the heart and darkness, hunger for every heart until the dark door opens.
  • After defeating Chernabog, you must venture into the now abandoned Bald Mountain. Inside, you'll find murals on the walls showing the wreckage of several Disney worlds, largely just the destroyed Princess worlds. Among them you'll find the animate trees from Snow White, just another casualty of the darkness.
  • The Neoshadows, who appear in the secret endings, also were added to appear in the final general combat area of the game before the final boss as special enemies. These guys are already scarier, bigger versions of the Shadows, and they definitely prove why they were added as basically the very last generic enemies of the game, as they're strong, vicious, and work as a unit. They really can make you dread what's to come in the series' future.
  • The Final Rest is a peaceful, pretty cave that has a Megalixir in a chest and the ominous door you encountered in the tutorial. If you try to enter the door, you're stopped, and Sora claims to hear a voice. It's the same voice from the tutorial (now known to be Mickey), who appears via the usual subtitle captions across the top of the screen (in a text box-based cutscene), with a dire warning.
    Careful. This is the last haven you'll find here. Beyond, there is no light to protect you. But don't be afraid. Your heart is the mightiest weapon of all. Remember, you are the one who will open the door to the light.
  • In Neverland, while traversing through Hook's ship, Sora is attacked by multiple doppelganger Heartless known as Shadow Sora - jet-black, no weapons, flies through the air, dances until it deems you worthy of receiving of an attack. When you defeat it, the experience point display reads Tech 150p. "Tech" points are normally rewarded when Sora parries an enemy strike. Then it hits you: Riku isn't just sending out clones of Sora; he's actively attacking him.
    • Not to mention the secret boss of Neverland, known as "The Phantom". It has a fitting ghost-like appearance, is difficult to beat, and has a special attack that instantly takes out your allies one by one, until going after you.
  • Oh, and while on the subject of Riku, the way he becomes when Ansem, Seeker of Darkness, takes over his body and turns him dark has to be plenty chilling. Especially the way Riku talks while possessed: he speaks with the voices of both himself and Ansem. Riku's own voice is dull and flat, and all the inflection comes from his "passenger".
    • If you finish the second Hollow Bastion visit before you finish the Monstro stage, you still tangle with "Riku", only this time, Sora makes it clear he knows it's not Riku who's kidnapping Pinocchio. Ansem instead entirely uses Riku's voice, and mockingly asks things like "Don't you wanna play with your best friend?" It's very unnerving.
  • The intro to the game itself is disturbing enough to keep you from playing through it AT ALL. From the unreal music to the all-consuming darkness surrounding your stained-glass prison of a tutorial space. The silence and lack of a voice or many other sound effects in the first stages doesn't help either. This all culminates with a massive shadow monster that you're expected to defeat, alone.
  • Speaking of Ansem, his "true" form actually looks like a downright Satanic Archetypeespecially his Scary Black Man-like skin combined with his sheer Supernatural Gold Eyes.
  • The Heartless. They could pop up anywhere at any time and start viciously attacking you. In a hotel room? Yep. In a local bazaar? Yep. In an African jungle? You betcha. Almost nowhere was safe in this game . Imagine what the inhabitants of the various worlds had to go through, Getting so much as a good night's sleep meant letting down your guard and leaving yourself open for a possible heartless attack. You would have to constantly be on the defense. Your heart would be an automatic homing beacon for every heartless in the vicinity and they would come at you relentlessly and even if you managed to fight them off they would come back again eventually.
    • Ever notice how there aren't many local residents in the game? The masses were probably purged through heartless attrition shortly before the events of the game.