At one point the game was to feature bosses known as Savants, which were basically brains in a jar which had evolved beyond having physical bodies. This was scrapped when they realized fighting brains in a jar was just not fun game play.
The game went through multiple incarnations during development ranging in time periods from the 1930s to the future. Rapture was intended to be very functional, looking more like an underground subway system rather than an underwater base. The style was considered just too bland and Art Deco was decided on.
Even though they were always called "Little Sisters" in the game design documents, the Little Sister was not always designed as a little girl but always needed to be a sympathetic character. Originally the Little Sister was going to be a slug, but it had no appendages and could not present emotion without a face. Several other designs were attempted such as a crab and a crippled dog. However, none of these designs were sympathetic enough, and the little sister became a small human girl.
The original name for the Gene Bank was Plasmi-Quik, but it was changed when play testers commonly avoided the machine because they were unsure of its purpose. The first video released of the game showed the Plasmi-Quik.
While in the game's development, the creators wanted Jack to mutate more and more with Plasmid use. This would then make the players have to decide if they wanted to become more like a Splicer to survive or refuse and keep their humanity at the cost of less safety. Unfortunately, the idea didn't make it into the final game.
A third Big Daddy model was scrapped prior to release, much to the dismay of some of the developers. Called SLOPRO this Big Daddy was designed with a shoulder mounted cannon and a large hook which it would use for lethal mêlée attacks.
It was explained that the reason that the player can see the ghosts of the residents of Rapture in the game is because that the ADAM in the city is moving constantly from person to person as they get killed. The ghosts you're seeing are just a result of the leftover RNA (memories) that you inject along with the ADAM.
Andrew Ryan's philosophy of a man having a "Right to the sweat of his own brow" is a sidelong reference to Ayn Rand's philosophy of "Objectivism", where morality is full respect for individual rights. Ryan's name is even a surname-reversed quasi-anagram of Rand's: ANDRew rYAN.
In one of Dr. Suchong's audio-diaries, he expounds on the science of the Vita-Chambers and comments on "plasmid reconstruction this and quantum entanglement that." In System Shock II, an earlier game that Bioshock's FPS-RPG gameplay is based on, you had to provide quantum entanglement samples to reconstruct your character after death.
There is an easter egg that can be found in the Arcadia Farmer's Market. If the player enters the Worldly Winery and goes to the right corner of the main lobby, they can find a Pac Man reference, with Pac Man being made out of cheese and bullet holes implied to simulate pellets.
The game underwent many development changes from the time it was pitched top the final product. The original concept for the game was set in a fifties style futuristic city that took place on land and inside interconnected controlled environment chambers. These laboratories would be full of dead human bodies and be filled with various insectiod life forms. One of these life forms, called Gatherers, would collect genetic material while being protected by a second form of life forms called Protectors from the last form of life forms, The Predatory Aggressors. These eventually developed into the Little Sisters, Big Daddy's, and Splicers respectively. When the developers decided that they wanted a more human angle to the game.
In all the bioshock games, the writer is also the director. For example, Ken Levine is the writer and director of bioshock and bioshock infinite, while Jordan Thomas is the director and writer of bioshock 2.
The Xbox 360 version of BioShock became backwards compatible for Xbox One on December 13th, 2016. Despite this just being the Xbox 360 version of the game running on Xbox One hardware, BioShock sees a massive performance boost. BioShock features an option to unlock its frame rate. When this option is engaged on Xbox One it causes the game to mostly run at 60 frames per second with only some momentary drops. When the frame rate is capped to 30 fames per second on Xbox One, BioShock never drops a frame. When running on its native Xbox 360 hardware, BioShock would still experience some frame drops when the frame rate was capped. When the frame rate was unlocked on Xbox 360 the game would experience wildly inconsistent frame rates that could range from the the high 20's to the low 40's, and this was coupled with non stop screen tearing (something that the Xbox One remedies since it enforces v-sync). The BioShock games were some of the first announced to be coming to the backwards compatibility program. It took nearly a year for them to finally come to the program, and in that meantime a BioShock remaster collection was released for Xbox One and PlayStation 4.
The trivia items below may give away important plot points.
In the beginning of the game, Atlas tells the player that he's got a son and wife named Patrick and Moira. Later on, when in Fort Frolic, the player can find posters for a show there titled "Patrick and Moira". This implies that Atlas used these names to lie to the player about having a family and also foreshadows the "Would You Kindly" plot twist later in the game.
There is an early hint to the games twist. In Neptunes Bounty, there is an audiotape detailing an endeavour of Andrew Ryans to limit usage of the bathyspheres to specific members of Ryans choosing. However, it doesn't work correctly as those related by blood to Ryan are also able to travel.