Rather than take the NeoGAF summary as fact, Shacknews has kicked up their own list of BioShock 2 details that have been officially confirmed by an unnamed source at 2K Marin.
While the below details were once unconfirmed, Shacknews has since verified that all of the following information is valid. Additionally, a few points have been updated:"Upgrade trees are now more diverse" sounds promising.
- The game is set 10 years after the first BioShock.
- There will be a multiplayer mode, but no details were given.
- The Big Sister is a grown-up Little Sister, and she's hunting you.
- Some levels take place on the sea floor outside of Rapture.
- The Big Sister will periodically pop up after you kill enough Big Daddies. Her arrival is apparently signaled by a Little Sister singing a song.
- The Big Sister is described as fast and "the hardest thing in the game." She'll utilize telekinesis to throw objects at you or use them as shields.
- Your drill overheats, and cannot be used constantly.
- As a Big Daddy, you'll be able to do that nifty shoulder bash move.
- Upgrade trees are now more diverse.
- The Incinerate plasmid allows you to throw a fireball or shoot a stream of fire, depending on upgrades.
- Plasmids can now be combined. For example, mixing Incinerate and Cyclone Trap will result in a flaming trap.
- Weapons and plasmids can be used at the same time.
- You can now heal damaged turrets and bots.
- Players will explore Fontaine Futuristics, which is where the Adam energy is harvested from Little Sisters. Through this, you will learn how the Adam is recovered.