Marathon was released for the mac Macintosh and was one of the earliest first-person shooters to appear on the Macintosh.
Set in the year 2794 A.D., the game placed the player as a cyborg Security Officer aboard the human starship U.E.S.C. Marathon, orbiting a colony on the planet Tau Ceti IV. Throughout the game, the player attempts to defend the ship and its inhabitants from a race of alien slavers called the Pfhor. As he fights against the invaders, he witnesses the three shipboard AIs' interactions, and discovers that all is not as it seems aboard the Marathon.
Forge (level editor)
Forge Patch - 1.0.4
Anvil (resource editor)
Anvil Patch - 1.0.3b4