Marathon

Marathon is a series of science fiction first-person shooter computer games from Bungie Software released for the Apple Macintosh between 1994 and 1996. It would go on to have a great deal of influence on the narrative, visual design, and gameplay of the Halo series.

In 1996, Marathon and its sequel Marathon 2: Durandal would be released as a bundle for Apple's short-lived home console, the Apple Bandai Pippin, as Super Marathon. In 2000, Bungie released the games' source codes and other assets, just prior to Microsoft's acquisition of the company. On August 1, 2007, a remaster of Marathon 2: Durandal was released on the Xbox LIVE Arcade by Freeverse. Since the original game hadn't been released, the Xbox Live version was renamed "Marathon: Durandal". 4 years later, the entire Marathon trilogy would be released on the App Store for free in 2011.

The Marathon trilogy is now available for free on Windows, Linux and Mac here, though the games require a source port (Aleph One) to work on Windows operating systems.

Marathon
Marathon was released for the Apple Macintosh and was one of the earliest first-person shooters to appear on the Macintosh. Unlike some other similar games of that era (for example, id Software's Doom) Marathon and its sequels, Marathon 2: Durandal and Marathon Infinity were notable for their intricate plots, predominantly told through various terminals.

Set in the year 2794 A.D., the player assumes the role of a security officer aboard the human starship UESC (United Earth Space Council) Marathon. The Marathon was constructed beginning in 2408 by hollowing out the Martian moon Deimos to produce a colony ship that was launched towards the star Tau Ceti. The story begins some time after Marathon arrives in the system and begins the construction of a colony on planet Tau Ceti IV.

The player is awoken by one of the Marathons three artificial intelligences, Leela. The player interacts with Leela through computer terminals found around the ship. Leela explains that the ship is under attack by an alien race, the Pfhor, who have also attacked the colony on the planet. She has been damaged in the attack, and the other two AIs, Durandal and Tycho, appear to have been disabled.

Throughout the game, the player attempts to defend the ship and its inhabitants from the Pfhor. As he fights against the invaders, Leela regains contact with Durandal, who has gone rampant. Leela eventually succums to the attacks, and Durandal takes over Leela's role in directing the player. For the rest of the game, the three AIs periodically appear as one or another contact the player, with a reanimated Leela ultimately left in control while Durandal leaves the ship.

Marathon 2: Durandal
Marathon 2: Durandal was the sequel to Marathon. In addition to being released for the Apple Macintosh, a Windows 95 version was also released. The game engine itself underwent several changes from its first incarnation. Although most of these changes were "under-the-hood," a few were visible to the user. The Marathon 2 engine offered performance gains on some machines, in addition to support for higher resolutions, higher color depths, and better quality sound. The enhanced engine also allowed the loading of maps from external files, allowing for users to (later) create and play their own maps.

Marathon 2 begins 17 years after the first game's ending. The player awakes aboard the Pfhor ship that Durandal stole, having beamed the player aboard as he left Tau Ceti. He reveals that after they left, a Pfhor fleet arrived and destroyed the colony. He further reveals that he called the Pfhor to Tau Ceti in order to steal their technology. Now they orbit the ruined S'pht homeworld, Lh'owon.

Durandal sends the player and an army of ex-colonists to search the ruins of Lh'owon for information that would give Durandal an advantage against the Pfhor, who are planning a new assault on humanity. Among the new characters in this adventure are Durandal's evil counterpart Tycho, who played a minor role in the first game; a Lh'owon-native species known as F'lickta; an ancient and mysterious race of advanced aliens called the Jjaro; and the long-lost S'pht'Kr clan.

Marathon Infinity
Marathon Infinity included more levels than Marathon 2, which were larger and part of a more intricate plot. The game's code changed little since Marathon 2, and many levels can be played unmodified in both games. Marathon Infinity was only released for the Apple Macintosh. The most dramatic improvement in the game was the inclusion of Bungie’s own level-creating software, Forge, and their physics editor, Anvil. Forge and Anvil allowed a new generation of players to create their own levels using the same tools as the Bungie developers themselves. In Forge, distance was measured in World Units, which are roughly equivalent to 2 meters (6 or 7 feet). Another improvement was the ability to include separate monster, weapons, and physics definitions for each level, a feature heavily used by Double Aught, who designed the Marathon Infinity levels.

Marathon Infinity begins as the Pfhor destroy Lh'owon using a Jjaro-derived doomsday weapon known as the Trih'Xeem (early nova). Unfortunately, the weapon also releases a powerful chaotic being which threatens to destroy the entire galaxy. Because of the chaos, or by means of some Jjaro tech of his own, the Security Officer is transported back and forth in time and through his own dreams, finding himself jumping between timelines and fighting for various sides in a desperate attempt to prevent the chaotic being's release. After multiple instances of "jumps," the player (seemingly the only being who realizes he is being transported between possible realities) activates the ancient Jjaro Station, preventing the chaotic entity's release. The ending screen of Infinity leaves the story's resolution open-ended, taking place billions of years after the events of Marathon Infinity.

Halo and Marathon
Halo borrows many visual and narrative elements from Marathon, although the series are canonically unconnected. For example, the Marathon logo is embedded in the original Halo logo and serves as the original Reclaimer glyph. The Halo universe's concept of rampancy, a form of insanity experienced by artificial intelligences, is loosely adapted from the Marathon universe's condition of the same name. The Spartans' MJOLNIR Powered Assault Armor and its "Mark" designation scheme are named after Marathon's Mjolnir Mark IV "battleroid" cyborgs, which include the player character.

The Mjolnir Security armor closely resembles the armor worn by Marathon's protagonist, a security officer aboard the eponymous vessel, and its helmet sports the series' logo. The M41 SPNKr rocket launcher takes its name and design from the SPNKR-XP missile launcher introduced in Marathon 2. The Halo series' plasma pistols are functionally similar to the fusion pistols from the Marathon trilogy. Hunters are remarkably similar to their Pfhor predecessors.

Trivia

 * The Halo 3 Marathon Man achievement, which is unlocked by finding all seven terminals, is a reference to the Marathon series' terminals, which are the sole source of in-game story progression. The emblem's icon is a stick figure with the Marathon logo for a head.