If you've played Volume or Thomas Was Alone, you're probably already familiar with indie developer Mike Bithel and his fondness for quirky, narrative-driven games. However nobody could've anticipated today's surprise release of Subsurface Circular, a short sci-fi title that follows the life of a robot detective.

Back in April, Bithel took to Twitter to ask his followers if they would be interested in a short, cheap game with a "unique feel/mechanic appeal," and the response was largely positive, though he didn't offer any other details on this mystery project at the time.

Subsurface Circular's pre-release marketing strategy consisted entirely of a short series of tweets that Bithel sent out just 5 minutes before the game launched on Steam. In an interview with Eurogamer today, Bithel explained that he wanted to create a game that "respects the audience's time", since many gamers already have sizable backlogs of lengthy games that they'll probably never finish.

Subsurface Circular plays similarly to a text adventure title, but with a modern twist. The game takes place entirely in a futuristic subway carriage, with the player investigating a string of missing robot cases. The gameplay consists of selecting from a large array of dialogue options in conversations with various NPC robots.

Though the game just came out a short while ago, it's already received positive reviews from the likes of Polygon and GamesRadar. If you want to check out Subsurface Circular for yourself, visit the Steam store page. Currently, the game is on sale for $4.79, but that offer will expire on August 24th.