In some ways it improves upon the original, but it also takes some steps backwards from its older sibling as well.
Though I didn't see much of an opportunity, story-wise, to create a sequel (unless they had used Bioshock 1's "evil ending"), 2K Marin did a fairly good job at creating one nonetheless. Bioshock 2 puts you in the shoes of the very first Big Daddy prototype, a broken monster that has been left face down in a pool of fetid water for almost a decade. Awakened by a familiar friend, you are tasked with the job of recovering the little sister you were originally programmed to protect...as well as stopping the big sister (Think little sisters all grown up and in diving suits) who is kidnapping young girls from the mainland.
Throughout your journey to accomplish this you'll encounter NPCs that taunt or aid you in your quest, the only difference from this game and its predecessor is that there will be times when you actually get to interact with them and can kill them if you so desire. In perhaps what is my favorite part of Bioshock 2, you are given the chance to alter the storyline by sparing (Or murdering) characters that you have every right to kill. This is a great improvement over Bioshock 1, since the only factor that determined whether you were good or evil was whether or not you harvested little sisters instead of rescuing them. You'll see the effects of this early on, when after sparing a certain enemy character this person changes their opinion of you and begins to aid your cause whenever they are able. Though overall I felt the story lacked the emotional punch of the first game, it just about made up for that with this unexpected feature.
As important as dialog and "Choice" are to a powerful video game story, I've always held the unpopular belief that graphics rank a very close second. Visuals can make a big difference in a game like this where the story relies on the odd looking surroundings to set the mood. While the engine moves much better this time around and doesn't have that old texture pop-up problem that nearly every other UE3 based game has, it does have a couple faults that should have been addressed before it shipped.
First of all, many ATI users have complained of horrible flickering and shadow problems in the game. As an owner of an ATI card I understand that Nvidia still holds the lion's share of the market, but I feel that with so many people experiencing this they would have fixed it before it went gold. Granted, this may be something ATI needs to fix with a profile update, so it may be too early to lay the blame on 2K Marin. Thankfully these glitches can be easily avoided by enabling vSync in the options menu. Though some gamers don't like the performance hit (or mouse lag) that vSync creates, I was fortunate enough to not see a difference. Still, it might cause a problem for die-hards that normally shy away from enabling vSync in their games.
Somewhat less of a problem is Bioshock 2's reliance on pre-recorded bink-formatted video files to show its cinematics. Though it's rare to be subjected to these scenes, it's quite jarring when they do eventually appear. Thanks to their low resolution and cloudiness, these intermissions look significantly different from the actual game...which meant I felt like I was being pulled out of the world whenever they appeared. Had they stuck to using nothing but in-game real-time scenes like the first game, they'd have avoided this completely. Though it's a small gripe, it bears mentioning.
Overall, the graphics aren't something you can speak positively about when reviewing Bioshock 2. While they aren't terrible, they are mostly unchanged from the first game. Several assets have been recycled, making the game feel like a 10 gigabyte expansion pack rather than a high budget sequel. Furthering this feeling is the fact that some of the textures appear to be very low resolution when compared to what the first game used. Many of the wood and item textures looked very pixelated and unfinished, much like what I saw in Bioware's Dragon Age. At first I thought it was a problem on my end, but a quick check on the forums showed me that both Nvidia and ATI users have complained of this. Apparently, they did this on purpose to speed up loading of the environment. While I can see the need to fix the horrible loading speed of the UE3 engine, I don't think this was a good way of going about it.
Bioshock's visuals may not be worthy of being called next-gen, but one thing it does manage to get right is its level design. While it does use many of the same assets as the first game, the layout of each new area felt more "natural" than Bioshock 1. In the sequel levels have been designed so that you very rarely need to backtrack since the quests you are told to complete within them are very linear and laid out in front of you like breadcrumbs. Though in an RPG I'd frown upon this practice, it works splendidly in an FPS. The straightforward level design makes the game feel much more like a standard shooter than its predecessor. I never once found myself returning to previous explored areas within a level just to finish a quest, and the only times I did backtrack were because I wanted to scrape up every last health kit I could get my hands on.
Furthering Bioshock 2's crusade against its predecessor's repetitiveness is the way you go about collecting Adam. Unlike Bioshock 1 where you merely killed a little sister's metal escort and snatched her away from him, the sequel forces you to accompany the girl around rapture as she siphons Adam-laced blood away from corpses. While it sounds basic, it is anything but. Not only do you have to carry her to these corpses, but you must defend her from the seemingly endless onslaught of splicers that are disgusted at your "theft" of "their" Adam. To prevent this, you are encouraged to set up traps and create a perimeter around the corpse in the hope that whatever enemies you aren't quick enough to stop will instead be taken care of by your traps. Contrary to what I've heard others say about this feature, I never once found it frustrating and actually enjoyed setting up traps for the clueless splicers to get killed by.
Once you gather two corpses worth of Adam with your little sister, you are then given a choice. You can remove the Adam-producing sea slug from her body to collect the most resources from her (thus killing her), or you can free her of its control and send her back through the vents to safety. Like the first game, this has the same consequences and benefits as before...only this time your continued meddling with rapture's spooky little child caretakers will result in a visit from the big sister.
Big Sisters are significantly tougher than the Big Daddies you normally deal with. They're faster, can climb, and will even latch onto walls Ninja-Gaiden style as they pepper you with high powered plasmids and the occasional leaping tackle. Initially, their abilities greatly outweigh your own, so fighting them isn't the same standard "Find some water/oil and electrocute/incinerate them until they're dead" way that you deal with Big Daddies. In this game, Big Sisters are the toughest foes you'll face and quickly earn your respect with their tenaciousness and ability to withstand your attacks. In time, you'll eclipse their strength, but not before earning your power through clever trap and plasmid use.
If you haven't figured it out by now, combat, in general, is handled much better than the first game. Bioshock 2 not only increases the re-spawn rate and difficulty of the enemies, but seems to put larger groups of them together as well. In the original game you were rarely faced with more than three splicers at once. However, in the sequel, it's terribly common to fight as many as 6 to 8 at one time. The game will often spawn half a dozen splicers on top of you when you least suspect it, literally dropping them through ceilings and onto your lap. This means that the old Bioshock 1 tactic of stunning enemies and wrenching them in one hit isn't a fail-proof solution to every fight. It also means that hacking security cameras and turrets are your best means of defense when these large groups appear. You know the game doesn't expect you to handle enemies by yourself when your hacking tool actually gains the ability to deploy miniature portable turrets.
Hacking, as it was handled in the first game, didn't take long until it became incredibly annoying. The mini-game used to represent electronic bypass was time consuming and mostly impossible to fail at. By the halfway point I found myself either buying out the right to hack the machines or just destroying them altogether. Thankfully they've changed things in the sequel by revamping the hacking mini-game to not only be much quicker, but also not requiring you to exit the game screen to complete.
It always seemed odd to me in Bioshock 1 how you could hack a turret with 3 splicers beating on you and not get hit. Time stopped while you hacked, no matter how dire your current situation was. In the sequel, time does not stop during hacking, so you can be attacked while circumventing Rapture's steampunk-inspired security. On the plus side, the little hacking window that pops up on the bottom of the screen is now nothing more than a colored meter that has you stop a needle on top of a "safe color" in order to accomplish your bypass. Stop the needle on green a few times and you win the mini-game. Stop it on blue and you not only succeed, but you get some sort of bonus to whatever you hacked. If you get skilled enough at this timing game you can make hacked turrets stronger, security drones tougher and alarms longer in duration. It's a very clever change to what was, in my opinion, a tragically broken system.
Also getting an overhaul was the research camera. In Bioshock 1 you had to take a dozen pictures or more of your enemies just to get a couple increases to your examination level of an enemy, however in the sequel your camera is a movie recorder and it captures your battle with an enemy as you use different tactics to defeat it. Varying up your attacks against the enemy while its being recorded will result in a higher grade. Do well enough and you can gain a couple levels worth of research in only two or three tries. For someone like me who found the first game's research system to be tedious and unintuitive, this is a great leap forward.
As pleasing as the gun-play and exploration may be, I think the game fails at making you feel like a true Big Daddy. Though the game explains your initial weakness as having been a side effect to your long dormancy and lack of contact with your bonded little sister, I feel that more should have been done to make you feel like a Big Daddy. While the drill is powerful, it's true usefulness doesn't come until you've used a "power to the people" station to increase its power, lowered its fuel drain, grabbed the Ice-plasmid add on for it, researched Big Daddies until you gain the drill damage boost and finally learn the Drill Dash maneuver. These won't all come together until the last quarter of the game, which means a very large part of the Big Daddy experience (the drill) doesn't really factor into combat much at all.
One of the failings of the first Bioshock was how incredibly easy it was until the very end. The sequel does the exact opposite, making the beginning of the game incredibly difficult but the last 1/4th of it a little more evenly balanced due to all of your activated abilities. I'd rather have equally balanced difficulty throughout the whole game, but I still found it preferable to the aggravating curve of challenge present in the first game. My biggest criticism would be the two "fixed fights" that you have to endure in the middle of the game's opening sequence. The A.I. makes you think you can survive them which results in you using all of your med-kits and rivets in a useless effort to win a battle that you will automatically lose. I know this was done for story purposes, but it's the same kind of tactic JRPGs employ and I find it annoying when you are tricked into using valuable ammo and supplies in a fight where you will lose no matter what you do.
When the good is weighed against the bad, Bioshock 2 actually manages to beat its predecessor by a nose. Taking everything into consideration, the game is a much better FPS than the original, even if the starter areas are unnecessarily frustrating and the graphics aren't up to current PC "standards". If that doesn't convince you, then you should know that while I never kept the first Bioshock installed after beating it, I'm keeping the sequel on my Hard Drive for future playthroughs. It's no System Shock 2 or Deus Ex, but it's a decent FPS with some very intense moments. Guarding the little sisters and fighting their larger counterparts are the two best things to happen to this series so far, since it not only helps alleviate the feeling of repetitiveness that the first game suffered from but it also adds the kind of tension that most console-ported FPS's seem to lack.
Though very far from perfect, Bioshock 2 is a much more complete game than the first. With more weapons, more weapon upgrade stations, more chances to gain Adam, the little sister adopting system, the improved hacking and the Big Sister battles, Bioshock 2 is an improvement over the original. The only thing they need to do in the inevitable third installment is to change graphics engines and do a better job of balancing the difficulty. Do that, and nearly all of the series' shortcomings will have hopefully been addressed. As it stands now though, Bioshock 2 is strong enough to stand on its own. I still feel it suffers from using an old engine and having to be toned down graphically for the consoles, but these were both problems the first one shared as well.
Fans of the first should be pleased, especially if they like the idea of choosing to kill or spare important NPCs rather than just have their alignment judged by their treatment of the little sisters. Though in truth, many hardcore fans will walk away expecting much more. However, If the idea of playing a re-tooled and therefore slightly improved "expansion pack" version of Bioshock 1 appeals to you, then you shouldn't feel disappointed by this sequel. Just do yourself a favor and wait for the price to go down. If anything, you'll be able to download a patch by then that will fix the graphical glitches and the field of view problem as well as improve the general stability of the game, which for some people hasn't been too great.