This is pretty much the same thing, only with some extra detail. (All hail the Wikpedia!)
The game starts in the year 1960, with the player underwater following a plane crash in the ocean, surrounded by debris. No introductory cut scene is displayed explaining how this happened, leaving the player to decide for themselves why they were on the plane. Nearby, a lighthouse is sticking out of the water, in the middle of the ocean. Upon getting inside and traversing the internal stairwell, the player finds a bathysphere submersible with a corpse inside. Upon removing the corpse and descending in the bathysphere (having nowhere else to go), the player eventually reaches an underwater city on the ocean floor.
A plot unfolds involving the crumbling city and the utopian society for which it was built. It began with a Howard Hughes-like industrialist named Andrew Ryan. Born in Russia in the early 1900s, he witnessed the rise of the Soviet Union, losing his entire family to the corruption that would plague it throughout its existence. He eventually escaped to the United States, becoming a wealthy and respected industrialist/inventor. At first he is a dedicated patriot, grateful to his new nation for rewarding his intelligence and determination with prosperity and fame. However, his devotion is tested by the Great Depression, the New Deal, and finally shattered by the atomic bombings of Hiroshima and Nagasaki.
Immediately afterward, in 1946, was when he withdrew from the world and built the underwater city. A hidden sanctuary for those Ryan considered to be humanity's best and brightest, the society was envisioned as the ultimate capitalistic and individualist paradise, with the elite achieving for themselves, rather than for the whole. Mocking the beliefs of common society, he named it Rapture. Protected by a network of giant sea walls and consisting of a cluster of enormous skyscraper-shaped hive towers, Rapture was designed to be entirely self-supporting, with all of its electricity, food production, water purification and defense systems powered by undersea volcanic openings. At one point, it is learned that Rapture's population numbered several thousand at its peak during the early 1950s, composed of those people Ryan viewed as the best examples of mankind. A large and tiered economy grew among the people, catering different quality products to different levels of the society. The city itself is inspired by Art Deco and has an appearance merging the futuristic and archaic.
A scientific discovery upset the balance of the society. Two scientists studying ocean-floor dwelling creatures discovered a species of sea slug that secretes pure stem cells. These could be used to enhance one's body, improving physical or mental capabilities, curing diseases and healing injuries. A young entrepreneur named Tenebaum invested early on in the research to gain control over the material. The substance, dubbed "ADAM", became so sought after in the society, that it became the dominant currency of the city. A "full-scale genetic arms race" broke out between Ryan and Tenebaum as Tenebaum's monopoly on ADAM threatened the current social structure. Ryan eventually won, but everyone in the city was permanently changed. During the war, it was discovered that ADAM could be used to modify one's body, combining technology and mutations to adapt and survive the conflict, but losing their humanity in the process. During the conflict, all natural sources of ADAM were destroyed, which eventually resulted in a major shift in the "ecology" of the city, as all inhabitants had become biologically dependent on ADAM to survive.
When the player arrives in Rapture, the city is in a state of disrepair, its vast underground living areas and laboratory complexes scarred by the effects of the civil war and poisoned by biological weapons. Low-level flooding is also found to be a problem, as the use of high-powered explosives and corrosion weapons during the war created small breaches in the city's sea walls, allowing seawater to enter some of the buildings.
As the player descends through the underwater city, he or she will explore the many levels of the giant undersea base, including the huge living quarters modules and the multi-floored scientific headquarters. Remnants of the last days remain in notes and recordings made by the citizens before and during the collapse of Rapture's society. Not only does this provide background, it also opens new avenues in the player's interaction with the ecology of Rapture.
Four main categories of enemies are encountered:
- Splicers: Deformed, genetically modified Rapture citizens who are now remnants of Ryan's army, the Aggressors cannot survive without ADAM due to their extensive biological modifications. They wear little or no armor, and normally roam the levels of Rapture, searching for other inhabitants to kill and steal ADAM from. As their name would suggest, they are aggressive and quick to attack, and will use their enhanced physical strength, group tactics and, sometimes, semi-biological weapons to kill all in their path.
- Gatherers: (Little Sisters) Originally to be portrayed as slug-like, genetically modified sea creaturesbut now shown as genetically modified children, the Gatherers were created by a scientist named Dr. Tanenbaum as a solution to the ADAM shortage. They extract the inert ADAM from the dead with the tools they carry and eat it, their bodies reprocessing it into a usable form. The team designed them so the player would have to make an ethical decision on whether or not to kill little girls to obtain much-needed resources. Nevertheless, doing so is severely difficult, due to their symbiotic relationship with the Protectors. According to lead designer Ken Levine, the Gatherers have a direct link with the main character. In a recently released audio file, Levine clarifies that the player cannot physically harm a Little Sister directly, but can "harvest" the ADAM from them (a process which they will not survive). This will be presented via audio, and a black screen.
- Protectors: (Big Daddies, or Mr. Bubbles and Mr. B as some of the Gatherers call them) Mute, lumbering bio-mechanical monstrosities, created to protect the Gatherers. They are heavily armored and wield high-powered weaponry, including a large drill. Their armor somewhat resembles a large diving suit. Most of the inhabitants stay out of the way of the Gatherers and Protectors. They will not attack you unless provoked and according to lead designer Paul Hellquist "Once you mess with them, you find out why no one messes with them." In a recent trailer/commentary for Bioshock, it was revealed that, despite their size and typically slow movements, they become incredibly fast once engaged, in some cases quicker than the player.
- Security Bots: Throughout the city of Rapture, they are called via alarm by various security cameras. Security bots appear to hover and fly using the same method as helicopters and are armed with machine guns. When disturbed, the security cameras' siren will sound and an unlimited supply of security bots will pour out for a limited time. The only way to take them down is to shut off the security system by using ADAM to turn it off. The security system can also be suborned by the player, either by "hacking" it or using the "Security Beacon" plasmid on an enemy.
There's some more on the customization that I'll get to tomorrow or something.