I recently made a detour to the magazine section of Barnes and Noble while waiting for a table at a restaurant. I picked up a magazine called "Play" that featured a Bioshock preview as its cover story which contained an interview with a Bioshock developer. The following is the information I gleaned.

Bioshock is not a traditional first person shooter. Yeah, everybody says that about their FPS, but 2k Games is for real when it says that Bioshock bends and blends the genre in ways that I don't think have yet been realized. Given my total understanding of the interview, Bioshock will be a decision-based thriller that uses FPS elements to battle baddies while featuring heavy RPG elements and creating only the minimal necessary linearity in order to advance the main plot.

The first thing I like about Bioshock is the setting. Let's examine why.
Aliens invade earth: seen it a few times.
An evil leader levies his army to dominate the globe: been there once or twice.
An underwater bathysphere built for an early Cold War utopian society where genetic alteration has run amok: that one's new to me!

Next, there is a really interesting protagonist/antagonist relationship between your character and the Big Daddies/ Little Sisters. Little Sisters, the sickly-creepy little girls, are the keepers of "Adam." They walk around with monster 2-gauge needles extracting Adam from dead residents. Adam is the stuff that your character injects himself with to achieve certain feats/powers like telekinesis, controlling baddies, and a host of other interesting options. You must have Adam to advance the plot, so you have to get it from Little Sisters. The only problem is the Big Daddies, the principal (but not lone) enemies in Bioshock whose sole jobs in life are to protect Little Sisters. Big Daddies are the behemoths in dive suits that would like to drill through your skull. After you defeat the Big Daddy you have a choice to make: help the Little Sister and get only a portion of the Adam, or kill her and take it all. The developer hinted that the sum of all your decisions would affect the plot of the game.

Finally, here's a drive-by of other interesting gameplay elements.
There are also a host of other characters in Bioshock besides the Big Daddies/Little Sisters with interesting subplots for you to complete for them.
The game never locks you into a room, gives you a pile of weapons/ammo, and forces you to dual it out with a baddie. You can always exit a battle whenever you like and reengage at any later time.
The environment looks to have a plethora of gorgeous textures and lighting effects stemming from the underwater setting.
There are many ways to use your head in defeating baddies. The developer mentioned one innovative technique specifically: Use telekinesis to pick up a teddy bear and move it into a flame, light the teddy bear on fire, use telekinesis to hurl it at the baddie to set them on fire.

After reading the preview I now understand why Bioshock doesn't feature multiplayer (to my knowledge). It's not a shooter for the ages that we'll all want to LAN, and I'm glad 2k Games didn't force that upon the game, because we've got plenty of those to keep us busy in 2007. As a single-player campaign I think it'll deliver a Resident Evil meets Oblivion meets Halo experience. You can visit the uber-cool Bioshock flash site here. You can also visit the official Bioshock online community, The Cult of Rapture, here.