The game is set in fictional dystopian city Rapture in alternative history 1968, eight years after the events of BioShock. The protagonist and player-controlled character is a Big Daddy, a being that has had its organs and skin grafted into an atmospheric diving suit. Among the first of its kind, the player-controlled Big Daddy reactivates with no recollection of the past decade's events, and scours the city in a vain attempt to relocate the Little Sister that he was paired with. When it becomes obvious that Rapture's leader Sofia Lamb will become responsible for the city's destruction, the Big Daddy attempts to overthrow Lamb and her army of Big Sisters.

CPU - Pentium 4 2.4GHz Single Core processor
System RAM - 1GB
Video Card - Direct X 9.0c compliant video card with 128MB RAM (NVIDIA 6600 or better/ATI X1300 or better, excluding ATI X1550).
Sound Card - 100% direct X 9.0c compatible sound card
Hard disc space - 8GB free space