Immersion is in the details, too. Everywhere in BioShock, there is something to see, hear, touch, examine, read or search. The walls are covered in old photos, paintings, advertisements and messages scrawled in blood. The air is filled with strangely outdated music, catches of song, snippets of announcements and the occasional scream or cry. The diaries of long gone residents litter the ground and their desks, safes, boxes, purses and, yes, bodies are all searchable. You probably won't... probably can't experience it all, but the fact that so many layers exist for absorption is what makes BioShock feel uncomfortably real.
Don't think for a second, though, that Rapture is just some creepy but stale museum. Most of its inhabitants are still very much alive, in one form or another, and they are surprisingly violent. Anyone expecting the game to be a shiver-inducing slow burn like Silent Hill will be shocked by the gore and vulgarity on display. The suspenseful buildup of the elevator ride down, for example, explodes when you're forced to watch a horrifying murder from behind the foggy glass door. As a creature known as a Splicer stabs a man over and over, the flickering lights seem to highlight the gruesome display rather than hide it.
Later, you'll encounter a female Splicer, hunched and crooning over a baby carriage. The strange scene, cast in shadow, gives you goose bumps. But when the Splicer wheels around and launches herself wildly at your face, shrieking an array of foul, unprintable words, the scene might give you a seizure.
You kill that particular creature with a wrench to her head, but the possibilities for combat are many. And although the "baby" in the carriage does end up being a handgun (seriously), traditional firearms are less important than the genetic weaponry you can equip into your DNA. Discover the Incinerate plasmid injection and you can instantly ignite an enemy from across the room. With the Electro Bolt plasmid, you can fry them with bolts of electricity and, with Telekinesis, you can throw harmful objects at them using only your mind.