Gameplay
While Marathon 2 retains many of the core elements of gameplay of its predecessor, Marathon 2 has a very different feel, primarily in consideration of the facts that it uses an expanded engine and the setting of the game is different. The game's interface has been changed, with the view of the player being much wider than in Marathon (which was smaller as to improve game performance) and now taking up the lion's share of the screen, displaying the player's health and oxygen bars horizontally at the bottom of the screen rather than on the left vertically above the motion sensor. Virtually all of the graphics and sounds have been replaced; instead of background music for audio accompaniment of gameplay, Marathon 2 employs ambient sounds such as wind or alarms. Unlike its prequel which takes place on the UESC Marathon ship, Marathon 2 takes place primarily in outdoor environments. Levels tend to be larger, open, brighter, faster paced and far more dynamic in nature than those of Marathon.
Marathon 2 adds one new weapon, the shotgun. Like the pistol, the player can wield two shotguns simultaneously if he finds two. Some of the dynamics of existing weapons have been changed, such as that of the pistol which now carries eight bullets per magazine instead of seven and allowing the player to use both fists. Some creatures have been added and others dropped, and the dynamics of some of the retained creatures have been changed. For instance, the civilians, completely defenseless in Marathon, now carry pistols they can use to defend themselves (and with which they will shoot the player if he attacks them). Items can teleport into a level, as can creatures, some of whom can also teleport out. Although the player still primarily replenishes health and oxygen at wall stations, Marathon 2 features health and oxygen canisters the player can pick up.
One of the most distinctive additions to the engine is liquid media in which the player can enter and swim. There are four types of media: water, sewage, lava and goo, the latter two being harmful to the player's health when entered. While submerged, the player can move around, use the run key to swim upward and out, or use his fists or fusion pistol (although use of such will backfire and harm the player). The player moves slower while under media than upon the surface, and loses oxygen, and while under lava or Pfhor goo, also loses health. Each pool of liquid media has its own dynamics such as flow direction, speed, viscosity and high/low tide, and in some cases the player can modify a media's tide level. Although there is no limit to the amount of media on a level, and each pool of media can have unique dynamics, no level can feature more than one kind of liquid media.
As is the case in Marathon, Marathon 2 uses computer terminals to advance the plot and allow the player to communicate with various artificial intelligences. The player communicates with Durandal and Tycho, both of whom were artificial intelligences aboard the UESC Marathon in the original game (Leela is almost entirely absent from Marathon 2). Because of the translation equipment installed in the player's character's suit, the player can also access S'pht and Pfhor terminals, which function in the same manner as standard terminals. Terminals in Marathon 2 can change level dynamics by means such as opening or closing doors or altering the tide of liquids, and are capable of teleporting the player not only out of a level but to other locations throughout. The mission of some levels is to access and read certain terminals. Unlike Marathon, Marathon 2 does not pause the game when a player accesses a terminal, leaving him open to attack while reading, in which case the game immediately stops him from reading.
Read more about this topic: Marathon 2: Durandal