Codename: Room is an experimental puzzle game inspired by Portal and The Stanley Parable. In it, players are placed into a single room covered with gray tiles. This room is not what it seems, however. This room can make images appear on the walls and create the illusion that you're in a place that you're actually not. Many things can happen in the room and it's up to the players to decide how far they'll go. Once players are inside the room, a mysterious voice will come in and be mysterious. He will inform the player that they're part of an experiment that revolves around the room. The player will then have to complete several challenges that involve both platforming and puzzle-solving skills. The mysterious voice will then judge the player's performance which will determine what ending the player gets (good, bad, or something in-between).

The demo for the game is currently available to download on Itch.io. A single run of the game will take about 10 minutes to complete but players are encouraged to play through the game multiple times due to the fact that the game has multiple endings as well as various other secrets and easter eggs.

The game will revolve around the character of The Mysterious Voice. This character appears as young and naive but eager to run a successful experiment. As the game goes on, it soon becomes apparent that The Mysterious Voice is in way over his head and might not exactly have his life together. Not much is known about this character or what his ultimate goal is but he encourages players to just sit back and go with the flow. The player, subject 243, simply find themselves caught in the middle of this whole situation.