If there's one thing garaunteed about Irrational Games' Bioshock, its that the game (whether good or bad) is going to be "Dark". Check out this video compilation of the levels that will feature in the game. With gruesome looking characters like the Big Daddy, according to lead developer, Jon Chey, you have to fight in BioShock, but you also have to know when to fight and who. If you don't mess around with a Little Sister, the Big Daddy is going to leave you alone.
