Subsurface Circular

The game was released for Microsoft Windows and macOS on 17 August 2017, iOS on 23 October 2017 and Nintendo Switch on 1 March 2018.

The player acquires "focal points" on achieving certain goals, which then can be used to question other robots to get more information to solve the mystery.

Theta One One is still experiencing the sense of loss when at the next stop it meets an infantry Tek who seeks to confess its sins.

At the next stop, the same fabricator that Theta One One first talked to that night comes aboard, and reveals it was the Red Tek others spoke of, and is leading this plan.

[3] Bithell was inspired by old text adventure games such as those he programmed as a youth on the BBC Micro, and decided to try creating a modern take on the genre with a short and focused narrative.

[2] Bithell planned this as a short game, one that would "respect [ones] time" to be completed within a single play session and not linger and remain unfinished as many AAA titles he felt can be.

Bithell considered this validation of the short-game model approach, though commented that his case may be exceptional since he is an established and recognized developer.

[14][15][16][17][13] Polygon reviewer Colin Campbell welcomed Bithell's idea of creating a series of short, experimental and narrative-driven games.

[17] Liam Croft of Nintendo Life praised the writing and called the game a landmark in interactive storytelling.

Designer Mike Bithell in 2013