Crimson Room

Crimson Room begins with a brief monologue in which the player clicks to advance the text displayed on-screen. The player character narrates their experience waking up, saying they had drunk too much last night and realising the bed they were sleeping in is not theirs and the room they awoke in is one unfamiliar to them. They question if they are in a hotel room, then deny it and conclude that they are trapped in the room and must escape.^[10][11] This plot is cursory and is not relevant to the remainder of the game beyond providing a scenario to introduce the player to the room.^[12]

The room is then shown to the player, with a crimson red ceiling and crimson walls, and the player may click on the screen to get out of the bed, allowing them to begin interacting with the room. The room is presented from a first-person perspective as a three-dimensional space, where it can be explored and interacted with in the style of a typical point-and-click adventure game. The player initially sees a door with a doorknob, and a desk, which has drawers and has a bowl and a stereo on top of it. They may investigate or attempt to interact with the objects they see in the room by clicking on them. Clicking on the door will tell the player that "It is a strong door", and clicking on the doorknob will reveal that "The knob does not turn". They may look at the room from different fixed camera angles by clicking on the edges of the screen to move their field of view towards that area of the screen. They may also see a closer perspective of specific objects by clicking on them, or reveal new, hidden angles of the room by clicking on certain areas of it. For example, the player must click a particular space near the edge of a mattress to then see the area between the bed and the wall.^{[11][13][14][15]}

Some objects found in the room are items which are collected when clicked and are added to the inventory of the player. The pillow on the bed in the room lifts up when clicked, revealing a golden key underneath, which the player can collect. The player can then select the key they collected from the inventory section of the interface, and click on a previously-locked drawer in the room to use the key on the drawer and unlock it, allowing them to open it and find a power cord inside, another item the player can collect. The power cord can be used on the stereo on top of the desk to power it, letting the player click on the stereo's power button to turn it on. Eventually, after solving every puzzle in the room, the player is able to collect a screwdriver and use it on the doorknob of the locked door, which lets them escape, completing the game.^[11][13][15]

Viridian Room, Blue Chamber, and White Chamber all follow the same basic format as Crimson Room, but feature new rooms and puzzles to be solved. The Nintendo DS version of Crimson Room lets players choose to play any of the aforementioned four games, and allows players to save their progress in the rooms so they can leave the game and resume it later. Players navigate the room by using the touchscreen to tap on specific areas of the room to search them or interact with objects, just as the mouse is used in the online version. The game's puzzles were changed only as necessary to allow the game to be played on the handheld console and without using the internet — a notepad in the original release of Crimson Room which showed a web address for players to visit was replaced with an in-game PDA in the Nintendo DS version.^[3] The PlayStation Portable release Crimson Room Reverse uses the console's analog stick in place of a physical mouse, and features eight games total: the original four games in the series, and modified 'Reverse' versions of each game.^[4][5]