Killer Instinct is a fighting video game, the third in the Killer Instinct series, originally developed by Double Helix Games, followed by Iron Galaxy under supervision of Ken Lobb and Rare, and published by Microsoft Studios, released as a free-to-play launch game for the Xbox One in 2013. The game is a reboot of the series, though some plot elements from Killer Instinct and Killer Instinct 2 have been retained. Development of the game involves individuals with histories in fighting games on both the developmental and competitive sides. It received positive reviews for its mechanics and engine, but was criticized for its initial lack of content. A second season of characters was released between 2014 and 2015. A third season, along with a port of the game for Windows 10, was released in 2