Developer: Human Head Studios
Release Date: July 11, 2006

So, first things first: this is the 2006 game called Prey, not the more recent 2017 game called Prey.

In keeping with the trend of melding the game source with a related engine source in order to play a commercially unavailable game, here's Prey, 2006 edition.

The brief history is that in the late 90's 3D Realms tossed their hat into the "cool tech with one word name" game with a game and engine called Prey. It had deformable terrain, portals, and a Native American protagonist. Ultimately though it is never finished or released. Years later, while develping Duke Nukem Forever they dust off the old concept and hand it to Human Head Studios. They use id Tech 4 (so, the DOOM 3 engine) to make the game, keeping the protagonist and the portals (and even shipping before Portal) but swapping out the deformable terrain for gravity defying sections.

Years later 3DR sold the IP to ZeniMax, who was having Human Head make a Prey 2, reportedly tangentially connected to the first game, but it eventually gets canceled. In 2017 they decided to attach the Prey name to Arkane Studios' otherwise unrelated System Shock homage project.

The game has been unlisted and unavailable for years now in a situation similar to NOLF 2 where the rights are ambiguous due to corporate shenanigans but if you have it, now you can play it on your Mac. Again.

Pro tip: if you have a physical copy you can still activate the CD Key on Steam and activate this otherwise unavailable title.