starts off with a bang as the plane you are in crashes into the Atlantic and you are left treading water. Thankfully, there seems to be a large spire close by and as you approach it, you see a door. Thus starts your decent into the strange underwater city of Rapture.
This crumbling and leaky "city of the future" has gone mad and the hundreds of scientists, artists and their families are roaming the hallways looking for something fun to do. The city was founded by a man who believed that humans should explore their creativity and scientific curiosity without government involvement or pesky things like morals getting in the way. Consequently, the inhabitants of the city have made some remarkable breakthroughs.
The biggest of these breakthroughs is known as ADAM. This is a way to manipulate your genetic code in order to increase your strength, endurance, speed and even unlock special powers. The powers that ADAM grants you are called Plasmids, which are a fairly major aspect of the game and because of that, there are quite a few types. The first one you acquire is the ability to shoot electricity from your hands. This will either stun your enemies or, if they are standing in water, kill them. Other abilities include controlling swarms of insects, ice blasts, forcing enemies to turn on each other and marking enemies as targets for the city's security system. The other genetic cocktails that ADAM grants are the stat-modifiers mentioned above called Tonics.
As a result of the invention of ADAM, the enemies found throughout Rapture are not only crazy, but super-powered. Enemies fall into three categories: Splicers, Little Sisters/Big Daddies and the city's security. Each type of foe requires very different strategies. For the most part, the Splicers are your grunts of the game. Some have guns, some have blunt objects, and some have other abilities. One or two of these baddies don't cause much trouble, but if you find yourself in a room full of them, you might have to rethink your strategy.
While the Splicers are encountered very frequently, they are also the least interesting. Throughout the game, you will run into little girls who remove ADAM from fallen bodies. If you take out the girl, you will be rewarded with a large supply of ADAM, but these Little Sisters are protected by large creatures in dive suits called Big Daddies. These guys are tough and always require some out-of-the-box thinking. Thankfully, they are nowhere near as abundant as the Splicers.
The last type of enemy is Rapture's security. This comes in several forms that work together. There are cameras which call out bots and there are also gun-turrets. What is interesting about this type of enemy is that you can hack them and get them to work for you (or more specifically, against the other enemies). Hacking is a mini-game that is similar to that old desktop game Pipes. You have a screen of tiles that hide tube parts. Clicking on a tile uncovers it and clicking on a tube part switches the one in your inventory with the one on the screen. The object is to build a path from the circuit's beginning to its end without tripping alarms or shorting out the system. The security system isn't the only thing you can hack; there are tons of machines found throughout the game that, when hacked, help you in your effort to escape. Ultimately, hacking is a nice diversion and way to take a break from the action of the game.