1999 mode goes beyond tweaking with health statistics — like most difficulty settings — by adapting the core experience to make things more challenging.

"I'm an old school gamer. We wanted to make sure we were taking into account the play styles of gamers like me," said Irrational Games' head honcho, Ken Levine. "So we went straight to the horse's mouth by asking them, on our website, a series of questions about how they play our games.

"94.6 percent of respondents indicated that upgrade choices enhanced their BioShock gameplay experience; however, 56.8 percent indicated that being required to make permanent decisions about their character would have made the game even better."

As a result, the 1999 mode will require you to manage every aspect of your character, with a Game Over screen concluding the experience if you lack the appropriate resources to respawn. Doesn't sound like much, but think back to when you last saw a Game Over screen in a modern first-person shooter. In our eyes, the lack of permanent deaths is a good thing — but like Levine says, it's all about catering to all types of player. Even the crazy ones.