STORYLINE: you, Subject Delta, is bonded with a single little sister called Eleanor. Elearnor's mother, Dr. Sofia Lamb, took her away and locked her up. To survive, you must fight splicers,trust characters, make decisions, and explore levels to find her.
WEAPONS: for an arsenal,you have a large array of plasmids and guns.guns include machine gun, drill`, and shotgun(theres much more)and plasmids include electro bolt, incinerate!, and winter blast(lots more).
NEW FEATURES:
dual wield:you can now shoot AND use telekinesis!
fast ammo change:it takes 1 second to change from trap rivets to rivets instead of 5.
new abilities:upgraded plasmids come with new abilities(ex. Incinerate! 2 allows you to charge it up, and when you shoot the flames bounce to another splicer)
little sister:you can now adopt little sisters.play bioshock 2 to find out whats so special about it
OVERALL:this is a very nice game,it balances creepiness and epicness, and will keep you entertained for a month, and possibly forever since they added multiplayer(wink wink)