Classic first-person shooter game for the Macintosh. Despite 2d graphics that these days seem cartoonish and only pseudo-3D geometry, had such superb gameplay (and a killer story) that people still play it many years later.

The Marathon series of games was created by Bungie Software Products Corporation, and were first-person shooter type (FPS), with both single- and multiplayer modes. Starting with the original in 1994, the series continued with Marathon 2: Durandal and concluded (perhaps) with Marathon Infinity in 1996.

Marathon distinguished itself in revolutionary ways: furious gameplay in real time over a local network (LAN). Intricate pseudo-3D level architectures. Superbly-realized active-panning stereo sound. Saveable recordings of games played. A real-time motion sensor that distinguishes friend from foe behind walls and around corners. Above all, a vast and erudite storyline that unfolded progressively throughout the series and alternately informed, amused and alarmed the player advancing through the scenario.

Well OK, the storyline is unmatched, but the best thing about Marathon was and is the gameplay. Few other FPSes (and there are now many) are as fun to play. Some reasons might include responsiveness, variety, and balance.

Responsiveness is the speed with which the game reacts to the player's control input—if it's fast, your character is nimble and can do acrobatic maneuvers like dodging a crossfire, or using recoil to jump to otherwise inaccessible places. If it's slow you lumber around like, well, a machine. Marathon is fast.

A sorry number of games consist of nothing more than "kill everything that moves, find the hidden doors/ keys/ teleport, move on to the next level, repeat." Ad nauseam. Sorry, but in my book the only one where that was still fun was Doom. Variety is a Good Thing, and Bungie made Marathon with an extensible architecture that allows players to design their own maps and physics, limited only by imagination and the game engine itself. Hundreds of these third-party levels are available on the Internet, some of them as good as the originals.

Fanatical attention to detail and balance are Bungie hallmarks. Backgammon and bridge have excellent balance, chess has superb balance, and Bungie's games have balance. In FPS terms, that means scenarios and maps are designed so their geometry and physics allow you to at least play even if you're a novice with ten thumbs, dealing with computer enemies by turning down the difficulty setting. But as you learn how to move, and to read the motion sensor, and how to shoot, and eventually, how to shoot while running backwards watching the motion sensor, you become aware that there are things you can do, places you can go, that you couldn't before. In other words, Marathon handsomely rewards skill improvement. It doesn't flatten out as you get better, it opens up. That's how it differs from the "clear room, find door, next room" variety of game...