Polybius is an abstract shooter for Playstation VR and PC (with Oculus Rift support) created by Jeff Minter and his small, long-lived indie studio Llamasoft. It is based loosely upon an urban legend surrounding a mysterious arcade game, possibly created by the government, which caused it's player base to suffer bizarre and varied side effects after playing.
The game itself contains no plotline to speak of, but as part of promoting the game Minter span an entertaining tale on the Playstation Blog about playing the original, urban-legend arcade game in the private collection of an anonymous collector and coming to shortly after playing with few memories of the experience other than "a really weird combination of exhilaration mixed with a deep-seated anxiety whose origin I couldn’t identify". Minter's version of the game is described as an attempt to recreate the positive elements of the experience without the dark, bitter aftertaste.
The player takes control of a low-poly spaceship speeding across various planes, tunnels, tubes and other such geometric shapes. Your controls are simple and mostly limited to weaving left and right and shooting a steady stream of bullets. Your objective is simple: "Do what comes naturally"... which in this case involves dodging obstacles, passing through bull-horn-shaped gates, collecting pill-shaped powerups and blasting the various abstract and esoteric (and often strangely familiar) shapes that act as enemies.
Passing through a gate increases your score multiplier, but also boosts your speed, requiring the player to make a judgement call between higher scores and maintaining control of their craft. Slamming into an obstacle costs you a shield and reduces your speed. Additional shields are rewarded at the end of each level, and the game ends upon either completing the 50th level or crashing your craft without any shields in reserve.
The Playstation 4 release of Polybius was critically acclaimed, especially in its Playstation VR mode, with long-running UK-based magazine EDGE giving it a 9/10 and describing it as "a profoundly consuming and transportive experience of eye-watering intensity that'll leave you dazed and bewildered in the best possible way."
Sales numbers have not been released, but Minter has described them as covering the game's development costs and then-some.
Polybius took center-stage for the music video of Nine Inch Nails' 2017 single "Less Than", which primarily involves footage of the game with the song's lyrics appearing as in-game messages.
As An Aside...
It's been argued that the original Polybius, as an urban legend, may have developed from a badly calibrated beta version of Tempest. Jeff Minter worked on, and arguably became famous for, the widely acclaimed Tempest 2000. This link may or may not be purely coincidental.