is a 2019 visual novel social deduction role-playing game developed by Petit Depotto. It was originally released in June 2019 for the PlayStation Vita, and was ported to the Nintendo Switch in December 2020, with a Windows version released in January 2022. It is also set to release for PlayStation 4, PlayStation 5, Xbox One and Xbox Series X/S in December 2023.
Gameplay
This game uses a visual novel role-playing game format mixed with an RNG social deduction game. It is single player and utilizes a timeloop structure to create new situations. Aboard a spaceship, the player and several NPCs must deduce who on board is a Gnosia, an alien-like creature that will kill the regular humans on board. The player works with the NPCs to suss out and nominate the potential Gnosia suspects and put them into cryo-sleep. The player can also be Gnosia, in which case they know the other Gnosia on board and will work together to try to eliminate the humans. The number of Gnosia as well as the number of NPCs on board as well as the player's role, is determined prior to each loop beginning. In addition to regular humans and Gnosia, there are other roles, including the Doctor (who can investigate the recently frozen NPCs and determine if they were human or not), the Engineer (who can investigate non-frozen characters to determine if they are human), the Guardian Angel (who can protect high-risk targets from elimination by the Gnosia), and the Bug (who is essentially playing for themselves, trying to stay alive to the end of the round and seizing victory for themselves, destroying the universe).
Throughout playing these loops the player will encounter many events with the other characters, which provides additional backstory to them as well as the universe they are in. In order to get to the ending of the game, the player must encounter all of these events first, many of which are locked behind a specific set of parameters for each loop. The game allows for an "event search" function on the ruleset screen, which lets you make it more likely to run into the events triggering.
Plot
In the far future, humanity has become a massive spacefaring civilization. However, one threat it must deal with is the Gnosia Plague, where people who have been infected with the Gnosia Plague feel compelled to murder other humans in the name of their god Gnos.
The player character manages to get a ride on a refugee ship escaping from a planet being ravaged by the Gnosia Plague. However, during the trip to another planet, the ship's computer LeVi detects Gnosia infection on board the ship and following protocol, instructs the passengers and crew to deduce which one of them is the Gnosia before the Gnosia kills all of the humans and the ship is forced to self destruct. However, the player quickly discovers that regardless of the outcome of the investigation, time loops back to the initial discovery of the Gnosia infection. The player also discovers one of the passengers, Setsu, has also been trapped in a series of time loops and they both agree to collaborate to figure out to escape their loops.
However, when time loops, the conditions are not always identical, as the number of humans and Gnosia can change as well as the identity of the Gnosia. Later, the player even gains the ability to manually adjust the settings for each loop as they play through numerous different scenarios. Eventually, the player learns from the shrine maiden Yuriko that Gnos is actually a collective hivemind of "cyberised" humans who uploaded their minds to an electronic database and use the Gnosia as a means to add more minds to their collective. Yuriko also points out that the player themselves are an anomaly, since the ship only finds out the Gnosia infection since the player is supposed to be the Gnosia's first victim, meaning the player has been looping to timelines where they have already died. Scientist Raqio also eventually reveals that the player and Setsu's time loops are caused by an entity called the "Silver Key", which attach themselves to humans and gather data through the time loops they experience. Once the Silver Key collects enough information, it leaves to a different universe to continue its life cycle.