Plain and simple, Bioshock is great from start to finish, even if you normally don't play first person shooters.
Imagine it's the year 1960. You are on a plane over the mid-atlantic ocean. In a freak accident, the plane crashes, landing you in the middle of the ocean. Just a bit of a distance away appears to be a tower of some sort. Having been the only survivor of the plane crash, and out in the middle of the ocean, you swim towards it. Soon you find out this is no ordinary tower, that it leads down to an underwater metropolis called Rapture. Although all is not well even when you get down there, as you soon realize that the denizens of Rapture are all violently hostile. Eventually you uncover the mystery behind all of what's going on with Rapture, and why it's all happening.
The game only has a single player mode, but it's amazingly fun from start to finish. Think of a first person shooter that is slightly horror themed, involves retro guns and almost futuristic gene splicing, with a roleplaying twist to it. Put those together, and that's what Bioshock is in a nutshell. Those looking for fast paced and frantic run-and-gun action will probably be disappointed by Bioshock, as the guns aren't the only stars. In fact, it almost seems like the guns take a backseat to the real star of the show: the story itself.
Although the story is extremely interesting, in the beginning it feels as though a lot is thrown at you too quickly to understand it. Thankfully, the game makes up for this as you go along and things are explained to you fairly quickly. Towards the end, you are left with a satisfactory feeling that what you didn't know at first when you entered Rapture is now clear to you.
Bioshock does have a linear feel, but it does it in a way that feels unique - certain actions throughout the game affect the characters you encounter, and may even affect your fate in the end. You will have to make decisions that sometimes question your ethical beliefs.
The guns themselves feel, reload, and sound extremely retro, with the ability to upgrade them they can also feel a little ahead of their time too. Unfortunately, my opinion is that the guns are out of place for the decade - revolvers, tommy guns, and the like were used around the 1940s-1950s mostly - the game takes place in the 1960s so the guns feel a little TOO old for the time period, but then again there's a certain story element that partially explains why this is.
Bioshock totes itself as a "Genetically Enhanced Shooter", and with partially good reason. Not only can you use guns as your weapons, but you can genetically enhance your character with Plasmids and Gene Tonics to give yourself extra abilities. While this is nothing particularly earth shattering, I haven't seen a first person shooter to pull this off really well, and explain it story-wise, especially for the time period this is set in. Just like guns, you will have to make critical decisions on what to upgrade first, upgrade later, or just pure give up ever getting the upgrade. While it's technically possible for you to collect many of the Plasmids and Gene Tonics, the game is crafty in that it only allows you to carry a set amount of these at a time, forcing you to juggle what to take with you and what to leave behind for now until you have another chance to swap out again. Dying in the world of Rapture is almost non-consequential, as if you are killed, you are instantly resurrected at a Vita-Chamber in the game. Due to this, the game may feel a bit too easy to those who generally try to avoid dying in first person shooters, using duck and cover tactics.
Graphics are done terrific in this game - water looks believable, the environment's lighting is suited to the underwater nature of Rapture, lights reflect off shiny surfaces, and as a bonus for all you Vista users out there, Bioshock has advanced DirectX 10 effects available if you have a DirectX 10 compatible video card, to top it all off with even the most subtle of effects. Of course this is not to say you cannot enjoy the game on DirectX 9, in fact it still looks terrific in that mode. My only complaint about the graphics would have to be certain surfaces reflect light off them that doesn't appear quite right, but this is negligible.
Sound is also top notch, however there are some notable issues with sound in the PC version, and unfortunately I encountered this on occasion - sometimes the sound will drop out entirely for a second and then chug along as if nothing ever happened. Some encounter it, some don't, but I did on a Creative Sound Blaster Audigy card. The issue seems to occur the most on security alerts with an alarm blaring and a security bot shooting at you. Other than these issues, the sound sets the mood for the game really well - you'll hear various ambient sounds, some creepy voiceovers, like the insane ramblings of your splicer enemies, to the "uh-oh" moments like when you hear the groan of a Big Daddy around the corner.
The game also has an assorted collection of licensed music you will hear throughout the halls and rooms of Rapture - but again, the music, like the guns, feels out of place for the time period, as most of the music is from the 1940s-1950s, and there's even an assortment of songs that were made as early as 1932. This doesn't detract from the feel of the game's retro effect however - it only adds to it, which is always a good thing considering.
Unfortunately, as was stated before, the PC does have it's fair share of technical issues, although I have encountered none except perhaps long load times and audio dropping out. For those who are concerned: The game IS copy protected by SecuROM copy protection, the game DOES require that you have the DVD in the drive to play, and online activation IS required to get the game to work. While it does seem a bit overkill, if you intend to play casually you generally will not run into an issue. But if you are absolutely against intrusive copy protection in games, avoid the PC version of this one and try the X360 version if you have that console instead.
All in all, it seems a lot of things were done right with Bioshock, and very little was done wrong. It's a winning package that's DEFINITELY worth the money you spend for it, just check to make sure you meet the requirements for the best experience possible - the requirements are fairly steep as far as the recommended goes, and for DirectX 10 you'll need at LEAST a fairly recent card (From time of this review) if you want to enjoy the DirectX 10 features the game has.