Prey for Mac

From Aspyr Media:

Prey is a groundbreaking first-person shooter that turns the genre upside-down with new gameplay features and next generation graphics. Breaking the traditional first-person shooter format, Prey introduces innovative gameplay elements including wall-walking, portals, spirit-walking and gravity flipping, which allows for insane eight player deathmatches.

Prey tells the story of Tommy, a Cherokee garage mechanic stuck on a reservation and going nowhere. His life changes when an otherworldly crisis forces him to awaken spiritual powers from his long-forgotten birthright. Abducted along with his people to a menacing mothership orbiting Earth, he sets out to save himself and his girlfriend and ultimately his planet.