Quarantine circular is the second game of its type from Mike Bithell Games, made using the same code as previous project Subsurface Circular. The game was developed over a course of approximately 8 months by the studio, and was released without any pre-release announcement in order to "keep expectations realistic" as with the previous project.
The Circular games are text based with simple character scenes playing in the background. The player character changes between scenes, and as the plot progresses the player can choose different responses to suit the situation, as well as selecting focus points to ask additional questions.
Player choice impacts the story, and the game has 6 endings the player can reach. A developer commentary integrated into the text interface becomes available after the first playthrough is complete, as well as a chapter select.
The game takes place on an isolated research ship with many scientific personnel. The crew encounter an alien which is contained on the ship deck, and claims to provide the answer to a cure for the most deadly plague humanity has ever seen which is sweeping across the planet. It is up to the player to decide who is and isn't trustworthy on the ship, and the best way to proceed.