Superliminal is a Puzzle Game by Pillow Castle Games, released through the Epic Games digital store on November 12, 2019. It is an expansion of a tech demo by Pillow Castle Games titled The Museum of Simulation Technology, adding a plot and utilizing different puzzles while retaining the same main gimmick: the size of any object the player can interact with, from chess pieces to the moon, can be changed by interacting with it and perceiving it differently. A trailer for Superliminal can be found here, while a full run of the original version of The Museum of Simulation Technology recorded by Pillow Castle themselves can be found here.
The plot of Superliminal focuses on an unnamed protagonist learning about dream therapy technology called "SomnaSculpt", capable of helping to deal with problems such as not accurately perceiving the problems of their life. However, something goes wrong during the procedure, and the player must navigate their own mind with the power of enforcing their perceptions onto the environment, hopefully finding a way to wake back up in reality.
- 20 Minutes into the Past: Portable stereos and clunky computer monitors about, along with explicit environmental mentions that the year is 1991.
- A.I. Is a Crapshoot: The Standard Orientation Protocol AI goes from being generally unhelpful, to blocking Dr. Pierce from contacting you, to deleting the emergency exit and trapping you in the dream permanently. But then it turns out that this was all supposed to happen, so the AI was probably Obfuscating Insanity instead.
- Alien Geometries: Some areas can be connected by doors on items you can pick up and move around, such as the trailer's example of a bouncy castle leading to a brick corridor. In the game itself, this corridor leads to an air vent overlooking the pool and bouncy castle.
- Arson, Murder, and Jaywalking: In one of the hallways, there is a list of the days of the week, with Murder" listed for Monday-Saturday, but Sunday says "Beans."
- Based on a Dream: In universe: toward the end, Dr. Pierce describes a dream he once had about a white-space world where perceptions influenced reality. The ending reveals that the protagonist's similar experiences were secretly part of Dr. Pierce's therapy plan, meaning that Dr. Pierce's dream inspired the whole shebang.
- Bland-Name Product: Some boxes are labelled "Idea" (over the IKEA logo).
- Book-Ends: The first object the player will have to manipulate is a chess piece blocking their path. The final puzzle also involves chess pieces, as you have to alternate them across a chess board to make a path, with the squares otherwise functioning as pits back to the room's entrance.
- Catchphrase: Almost every single radio transmission begins with the words "Hello. My name is Dr. Glenn Pierce." Becomes lampshaded by the Standard Orientation Protocol when she starts blocking him. "Hello. My introductions are redundant."
- Deliberately Monochrome: One of the final sequences is purely black and white.
- Depth Deception: In addition to objects being only as close or as far away as the player perceives them to be, there are occasionally walls painted with illusions, such as a corridor that looks just like an ordinary wall until you walk down it. Some objects have to be created by lining up the depth deception properly, and others can disappear into depth deception illusions.
- Featureless Protagonist: Nothing is told about the portgonist of the game, and we never see the appearance of the protagonist.
- Foreshadowing: An early whiteboard has a few; it contains diagrams of the modular portal frontage and cloud inserts seen in later chapters, as well as a reminder to buy more red paint, which makes sense after the horror-esque segment ends with a reveal that all of the 'blood' the player's been seeing is just paint.
- Fun with Acronyms: The player's dreamself has been placed into SomnaSculpt's Interactive, Lucid-Induction Dream State, or I-LIDS.
- Hidden Purpose Test: Everything that goes wrong... doesn't. It's the real test, to force the protagonist to look at problems in new ways, even when they seem impossible.
- Journey to the Center of the Mind: Superliminal takes place entirely within the protagonist's dream world.
- Lotus-Eater Machine: The SomnaSculpt.
- Matter Replicator: The gimmick for one sequence of the game is that, instead of picking up and altering an object, you make a copy of it at whatever distance away you could have perceived it to be.
- Meta Twist: The first two areas are meant to be an introduction to the game's mechanics, such as resizing objects and turning images into real things. In contrast, the third area is themed entirely around a single object (dice), but changes their properties with every single puzzle. A whole dice may actually be two halves put closely together, or the end of a huge column you can only slide around instead of pick up, or a bunch of very tiny boxes that only break apart when you first attempt to use it as a platform...
- Mind Screw: The whole game can feel rather screwy, as altering perceptions is a key mechanic. For example, you may need to stand in a specific location so an image of an object becomes real, and then turn it around to find parts you could not have seen before.
- Mission Control: The entire procedure the player is undertaking is overseen by Dr. Glenn Pierce, of the Pierce Institute, as well as an artificial intelligence with a female voice. Unfortunately, after the initial observations, they lose track of where exactly the player is within their own mind, and can only occasionally chime in to offer advice.
- Nothing Is Scarier: One sequence takes place in a dark and bloody version of the hotel, with stacked boxes of DIE(t) soda propping doors open, other doors with bloody hand prints suddenly closing and locking before you can interact with them, and a knife that disappears if you interact with the flashlight casting light on it. However, nothing in the game is actually capable of harming the player. And then you reach the restaurant at the front and you discover that all of the 'blood' you saw was actually just paint spilled during an exceptionally messy redecoration.
- Perspective Magic: The main mechanic of the game.
- Puzzle Reset: There is always an option to do this when you get stuck which is located in the pause menu.
- Reality-Breaking Paradox: The protagonist must intentionally cause one to escape, by throwing a replica of the institute's strip mall storefront out its front door from inside of itself.
- Set Piece Puzzle: Most of the game's puzzles are in distinct groups of rooms, with barriers preventing the player from carrying items from one to another.
- Word-Salad Humor: One of Dr. Pierce's messages is played with the words in the wrong order, but read out as if it's exactly the way it's supposed to be."Hello! Name is my Pierce Dr. Glenn."