Perhaps the defining game in Mac gaming.

User Rating: 9.4 | Marathon 2: Durandal MAC
Marathon 2 was the sequel to Bungie's Marathon, and came out in 1995. Ever since, FPS have moved on to full 3D environments, realistic graphics, surround sound, and cinematic presentations. Similarly Bungie is now world famous for its Halo franchise, rife with its own hidden Marathon logos all over the place, and as I'm writing this getting ready to release the second installment in that series. The Marathon franchise was arguably the best Mac-exclusive franchise ever - by a long shot. (M2 did make it to the PC, but far too late to have any impact.) It started with Marathon in 1992. Before even Doom came out, Marathon was sporting nearly as many multiplayer options as Halo now does, and a captivating, story driven, detailed, epic first person experience. You could argue with them on gameplay, or perhaps on graphical style; but Mac users were way ahead of PC users for years. Marathon 2: Durandal, did everything Marathon did, only better. The graphics had been polished to new heights. The single player gameplay became that much richer with the inclusion of new, fighting BOBs (civilians BornOnBoard), that would fight alongside with you in AI that was ahead of its time. And the multiplayer got some great new options. Not to forget the rich, detailed story, or the incredible Durandal. Cortanna is but a second rate character next to the original three: Leela, Durandal, and Tycho, the three rampant AIs of the UESC Marathon, mankind's first deep space colony ship, sent off to Alpha Centauri. The story was told through a series of beautifully written terminal messages, either as glimpses of what had been left behind, or as messages from one of the AIs that were trying to manipulate you into doing their bidding. Also let us not forget the amazing modability of the game. Bungie was one of the first companies to straight out offer mod support, and help the community create the tools for it. The community that resulted was incredible, and the replay value of the product astounding. If this game had been a PC release then, I know it's blasphemous, but believe me, a lot of us wouldn't be talking about Doom the way we are today.