Prey 2 was a first-person shooter initially in development by the original Prey development team at Human Head Studios. The project was rumored to have been taken from Human Head and given to Arkane Studios to salvage, but before the rumor could be fully confirmed or denied published Bethesda announced the project's cancellation in October 2014. There have no reports regarding the game restarting development since.
What Prey 2 was supposed to be was a sci-fi first-person shooter where the player took on the role of Killian Samuels. Killian was captured by aliens on Earth, only to gradually become a sort of bounty hunter in an alien, hyper-futuristic city. He hunts down criminal aliens with an assortment of technology at his disposal including rocket boots, stasis grenades and all of the rockets and guns a future desperado might ever want. Add in plenty of free-running and you've got a modern action game, right guys?
While the development of Prey 2 has ended, the game did exist in some sort of alpha state and press even had access to a preview build of the game. That's all in cold storage now, however, unless Bethesda decides to eventually bring the franchise back from the dead.