Killer Instinct is a fighting video game, the third in the Killer Instinct series, developed by Double Helix Games, Iron Galaxy Studios, Rare and Microsoft Studios under supervision of Ken Lobb, and 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.
The game is available in three different packages. Here you can find the official news release. And the Season 3 trailer can be seen below: