Quarantine Circular is a text-based adventure game developed and published by Mike Bithell Games (The creators of Thomas Was Alone and Subsurface Circular, neither of which need to be played to understand this game). The game was released for Windows-based personal computers in May 2018.
In the middle of a global pandemic, a group of human scientists have located an alien at its heart, and must work together to discover its true intentions. Players alternate between the perspectives of the various staff members aboard a ship that's researching a cure for the plague, and Gabriel, the alien being contained against its will.
This game makes use of the following Tropes:
- Age Is Relative: Gabriel's main motivation for trying to help lesser civilizations is because of how brief sentient life is compared to the billions of years it can take to develop.
- Alien Non-Interference Clause: There's The Order, which eagerly enforces it, and then there's the group Gabriel's a part of, which is willing to interfere to prevent extinction-class events.
- Ambiguous Gender: When first conversing as Gabriel in the third segment, the player can decide whether they want the alien to be addressed as "he", "she", or "they", which doesn't change their appearance in the slightest.
- Closed Circle: As befitting a story with "Circular" in its title, all of the main cast is confined (or "Quarantined") on a ship while trying to discover a cure...and the alien's intent.
- Do Not Spoil This Ending: As with Subsurface, there is an icon on the start-up menu that requests Youtubers and Streamers not to spoil anything beyond the first three segments of the game.
- Double-Meaning Title: There's the literal "Quarantine" caused by the pandemic, and then there's the existence of a vast galactic empire that has put Earth in "quarantine" until they're naturally advanced enough to interact with other sentient life. There is even the Circular area that Gabriel is initially Quarantined in.
- Fantastic Racism: Commander Teng towards Gabriel.
- Hostile Show Takeover: The majority of segments are from the POV of a single character, but Teng interrupts Alla towards the end of Segment 5 to put Gabriel down.
- Humanity on Trial: If Teng is bargaining for the cure in the end, her constant antagonism has made Gabriel question whether or not her people deserve any help.
- Humanoid Aliens: Gabriel, with two arms, two legs, and human-like posture despite a radically different head.
- Multiple Endings: There are eight, including:
- If the restraint was released in Sequence 1 or 5, and Teng took the brunt of Gabriel's charge in Sequence 5, Alla can either volunteer to be infected with the completed tailor-phage, let Gabriel roam the nearby cities and spread the phage to the populace, or simply evict them from the ship.
- If Teng dodged the attack, she can either negotiate Gabriel's freedom for the tailor-phage, lets them leave with the cure while insisting humanity can take care of itself, or just stun them and take the cure while leaving them at the mercy of The Order.
- If neither Marc nor Alla deactivated the restraint, then Teng's stun will destroy Gabriel's research. Marc can then choose whether or not to let Gabriel help the Teks along to inhabit the Earth after humanity's extinction.
- My God, What Have I Done?: If Alla befriends Gabriel, and Gabriel sends her into a coma when Teng dodges an attack, it dramatically affects the alien.
- Never My Fault: Teng insists that Gabriel's copilot injured one of her men as justification for killing them and distrusting Gabriel, whereas Gabriel insists that Teng attacked first without a just cause.
- Power of Trust: If Marc or Alla trusts Gabriel enough to remove their restraint, then although Gabriel later betrays that trust by attacking a crew member, this leads on to the development of a cure being available.
- Shock Collar: How Gabriel is initially contained; he cannot leave the circular helipad markings on the ship he's aboard without getting shocked.
- Stealth Sequel: There's mention of Teks from Subsurface Circular, but only in the story branch where Marc needs to decide if they'll be humanity's successors.
- Story Branching: There are route splits dependent on two key factors:
- Whether or not you choose to disable the Shock Collar in Segments 1 or 5; leaving it enabled spares all the crew but ruins the cure, and has the last segment be a return to Marc's POV, while disabling it leads to the second factor.
- Whether Teng takes a blow from an enraged Gabriel meant for her, or dodges and lets Alla get hit, in Segment 5; whoever is uninjured will be the POV character for the final segment.
- The Name Is Bond, James Bond: An option for how Marc can introduce himself to Gabriel, who then briefly thinks his name is "Perez Marc Perez".