BioShock was one of the most highly acclaimed games of the decade. The graphics, story and gameplay were all praised universally for going above and beyond the standards set by story-driven first-person shooters up to that point. Now, the sequel to one of the best games of recent years is set to be released this week. BioShock 2 will be hitting stores Feb. 9, but you don’t have to wait until then to get the details. Developers and designers from 2K Marin and Digital Extremes recently gave an interview in which they explained the ins and outs of their highly anticipated sequel.

BioShock 2 takes place 10 years after the original game. Players still explore the underwater dystopian city of Rapture, but this time they step into the suit of the prototypical Big Daddy, someone who has had their skin and organs permanently attached to a diving suit outfitted with a rivet gun and large drill. Like the Big Daddies seen in the original game, you will encounter several Little Sisters, who you can choose to rescue, harvest for a genetic currency known as ADAM, or “adopt” so they will collect ADAM for you from fallen enemies.

The choice between rescuing, harvesting or adopting Little Sisters plays into the moral choices you’ll make in the game.

Jordan Thomas, creative director at 2K Marin, explained, “It’s still kind of primal and sad and, in some ways, uplifting depending on how you treat them. So you are still called upon to make those choices, but you’re not forced to mistreat them. In fact, what you do with that trust is part of how your choices affect the ending.”

Whereas the original BioShock only gave you the choice to save or harvest the Little Sisters (and become “either Jesus or Hitler” as some critics acerbically pointed out), BioShock 2 “makes it harder to be good and more rewarding to be really, truly evil with the Little Sisters,” added Zak McClendon, 2K Marin’s lead designer. “If you just straight up save the Little Sisters and never engage in adoption, you are going to be starved for ADAM. We’re hoping to make the choices with the Little Sisters a little more grey.”

Hogarth de la Plante, lead environment artist at 2K Marin, confirmed that the single-player campaign will feature all new environments. Though the game still takes place in Rapture, every area we see will be a new experience.

“We felt like there were a lot of areas we imagined in the city that we never got to see, and we wanted to maximize that for players,” he said.

The biggest addition to BioShock 2 is the new multiplayer mode, something not seen at all in the original. In the multiplayer scenarios, players are actually transported to a time just before the story of BioShock takes place, in which the citizens of Rapture erupt into a civil war to gain precious ADAM. Players choose a citizen of Rapture to play as and then engage players online (though sadly, not offline or over a LAN) in a variety of multiplayer modes to earn ADAM and progress through the ranks. Most maps will also feature a randomly placed Big Daddy suit, allowing whichever player who finds it to become an unstoppable killing machine.

Mat Tremblay and Jesse Attard, who designed and programmed the multiplayer aspect of BioShock 2, were very ebullient about the results. Jordan Thomas of 2K Marin agreed.

“We feel strongly, and the guys at Digital Extremes agree, that translating those events into multiplayer mechanics is extremely honest. You get to compete over ADAM without losing narrative vision,” Marin said.

In the single-player mode, numerous gameplay elements have been tweaked, changed and improved greatly. One of the most significant changes is the addition of dual-wielding. In the world of BioShock, guns are only half the story, as you will also be equipped with “plasmids,” genetic superpowers that let you shoot lightning, summon swarms of bees, and many other powers. BioShock 2 will let you have a plasmid and a gun equipped at the same time, instead of having to constantly switch between the two.

Hacking turrets and doing research are back, but they have been integrated into the combat mechanics to make the entire experience smoother.

“We want to encourage players to experiment with their toolset instead of using the same tactics over and over again,” McClendon said.

To that end, he confirmed that part of doing research on enemies will be a grade (A to F) based on how creatively you kill them.

Vita-Chambers, which gave the player an instant respawn in the first BioShock, were accused of making parts of the game too easy, because a player could go up against a particularly tough opponent, die and immediately go back to fighting without any kind of penalty. Vita-Chambers are back in BioShock 2, but they have been revamped to maintain a level of difficulty. When your health is depleted this time around, a Little Sister will come and heal you little by little, and it may not restore all of your functionality. Additionally, you will have to defeat tough enemies all in one go, instead of being able to abuse a cycle of dying and respawning.

BioShock 2 has some awful big shoes to fill, and the development team confirmed that the greatest challenge in making the sequel great was that the original game was so universally loved. Nevertheless, all signs point to BioShock 2 being another intense, emotionally packed adventure that fans and newcomers alike will not want to miss. BioShock 2 is being released for the PC, Xbox 360 and PlayStation 3 on Feb. 9, 2010.