There's no doubt that revisiting Rapture isn't quite as special as seeing the dilapidated underwater city for the first time. While BioShock 2 doesn't make you trawl through the same locations, there's a familiarity here, but with 10 years having passed since the end of the original game, new enemies are on the prowl, there's a new dictator in town and the big daddies are no longer alone as the top dogs. A new threat, in the shape of big sisters - agile, plasmid wielding, screaming death merchants - will have you on your toes, fearing for your life every time you hear one of their terrifying, wall-shaking shrieks. Thankfully, when it comes to holding your own in a fight, you're no slouch either. This time, you are a big daddy.
"But I've already played as a Big Daddy," you cry. Yes, while the end of the 2007 game let you put on a big daddy suit, it didn't make you feel like one of Rapture's little sister protectors. This time you awake as the very first, the prototype big daddy, and you're far more agile than you'd imagine. Not wanting to spoil the plot, you're without your little sister and you'll do anything to get her back. With a cast of characters, including new ruler of Rapture Sophia Lamb, all trying to stop you, the fight through the run-down corridors deep under the sea won't be easy.
Straight away you'll notice an important change over the original. Instead of having to swap between a weapon and a plasmid attack (the game's genetic enhancing super powers), you can dual wield. Your daddy's left hand can shoot out electric, fire, ice, and more mutant-like attacks, with one corresponding shoulder button used to cycle through those in your inventory (hold down to bring up a radial menu) and the other to fire. Your right hand holds a weapon, which defaults to a devastating drill. Providing you're carrying some fuel, this drill can be spun and used to rip apart roaming splicers - Rapture's Adam-addicted crazies.
Use of plasmid powers is very similar to how it was in the original game. Obtaining new plasmids requires Adam, a substance found in sea slugs, and grown inside the stomachs of young girls. Throughout BioShock 2 you'll be able to exchange Adam for new plasmids, but to use them you'll have to be stocked up with Eve, found in needles scattered around the city. Adam can also be used to upgrade your plasmids, giving them extra abilities (such as chain attacking enemies and shooting out icicles), while gene tonics grant you bonuses like increased speed and an electrical discharge when attacked.
Your drill isn't the only weapon available to you, with shotguns, machine guns, rivet guns, rocket launchers, dart guns and more all options once you find them. As with plasmids, all of these are upgradeable, not through a currency, but at upgrade stations located at special locations in the city. Each station can only be used once, and with each weapon having three upgrades, what you choose will shape how you tackle combat in the game. For example, your shotgun will gain the ability to shock enemies once fully upgraded, but you might prefer to use a station to improve the power of one of your other weapons. BioShock 2, far more than its predecessor, encourages you to use all your available tools.
Key to how 2K has managed to do this is the way in which enemy encounters occur. While moving about you'll run into splicers, including some new types such as the tank-like Brute splicer, and have to contend with security cameras and turrets, but at certain points you'll set up siege-like scenarios. When you come across little sisters you're able to harvest them or adopt them. Harvesting will instantly give you some Adam, but adopt and they can be used to get you a lot more - and more Adam means better plasmid abilities. Certain splicers can be drained by the little girls, but doing so will draw all splicers to that location, forcing you to defend her while she works away with her needle.