Bioshock manages to stay afloat despite it's flaws.
The game starts with a plane crash and you swim to a lighthouse and take the elevator down to Rapture. It's an underwater city build by the "crazy" genius Andrew Ryan as a last refuge against the stupidity of our conventional society. The ideology of Rapture is that of objectivism that states that humans must seek their own happiness as the highest goal of life even at the expense of others if it's done as objective self-interest. So Rapture is supposed to be this wonderland for creative successful people but something has gone horribly wrong. You enter the city in the aftermath of this event and must discover what happened. You are quickly contacted by Atlas who then proceeds to give you objectives to drive the narrative forward. I will not spoil the story here but say that those who have played System Shock 2 know pretty much what will happen. Another problem with Bioshock's story is that not much is happening while you are there. You find audio-logs from the people that used to live in Rapture that give a compelling story to what went down but most of the game for you is just moving from A to B to C etc. Even worse is the fact that often you will get a simple objective like walk to the next room and then something will happen that prevents that like the ceiling will collapse, ice have frozen the door, you need to save the trees, and many other contrived game elements to prolong the game and it often feels artificial. But overall the story is decent and will keep you interested enough to finish the game that should take about 15 hours and hence it's a game of good length.
Atmosphere is where the game really shines. The underwater city of Rapture is brilliantly crafted and very moody as a kind of a tribute to the early part of the 20th century. The city is created to be a haven for the rich and beautiful and you will find all manor of amusement like bars and restaurants etc. There are lots of neon signs, art and pretty furniture in Rapture and everywhere you go there are windows to gaze at the wonder of the sea with fish swimming around outside. The graphics help to accentuate the grandeur of Ryan's dream of a better place. Run the game in DX10 mode and you will have the best water effects ever created in a game. The graphics might not be as realistic as those seen in Crysis but they help to create the mood better. The dream is crumbling and water pours into Rapture through cracks and other openings and the sea is slowly reclaiming the area. To further create a mood of doom you will see Big Daddies walk around like golems and protecting Little Girls. You will be attacked by Splicers that are Bioshock's version of the zombies from System Shock 2 although they are nowhere near as scary. I simply cannot stress enough how great the atmosphere of Bioshock is. Everything works together to create an immersive feeling that not many games can match. Sound only helps to demonstrate this. The voice acting is for the most part superb. Andrew Ryan sounds like a madman with great dreams that couldn't bare reality. The audio-logs convey the downfall of Rapture and hence work to build up tension as they tell a tragic tale.
Gameplay is a mixed bag in Bioshock. Gone are the RPG elements from SS2. You no longer have stats and your inventory is now invisible so you can't sort it out and decide what to keep and use. You can carry any gun you pick up but the amount of ammo you can carry is limited and the same with the amount of money you can carry. You can get various upgrades called Plasmids and Gene Tonics. These plasmids and tonics can give you various abilities like shoot ice and fire from your hands, bypass cameras, become invisible, make you stronger etc. It's all pretty much standard fare and some that doesn't make much sense like the fact that you can shoot bees at your enemies. The problem is that you pretty much get enough plasmids and tonics to max out everything you want in the game. It's the same with the guns where you get enough ammo and first-aid kits/eve hypos to go medieval on all the enemies of the game. This is made even worse by Vita-chambers that let you revive at no penalty and because there are so many of them they ruin the challenge of the game. The 1.1 patch did give you the option to remove them however. Also I have to mention that if we strip all the fancy graphics away and treat Bioshock as a straight shooter the game isn't that good. You pretty much fight the same enemy over and over again during the entire game. There are a few different types of Splicers but they all look pretty much the same. Then there are the Big Daddies and Elite Big Daddies but due to the Vita-chambers and abundance of healing items they aren't scary in the slightest. In fact Bioshock isn't scary at all. Also the shooting mechanics just seem off to me. It's not lag but your aim always feels a bit off compared to other shooters. Often the graphics get in the way with "blurry effects" and distortion of vision etc. It's done to enhance immersion but it ends up being annoying because the effects prevent you from aiming properly.
Let me say that Bioshock isn't by any means a bad game. The biggest problem is that the game feels like a "dumbed down" version of System Shock 2. The game is very pretty to look at and the atmosphere is terrific but the gameplay is just subpar compared to the truly great games in the FPS genre. I don't like games that are difficult just for the sake of being difficult but I do like consequences in my games i.e. that my actions matter to the story and game world and that isn't the case with Bioshock. The moral choice you make in the game is purely black or white and the game lacks a soul because of it (if videogames can have a soul that is). So to finish this review let me say that Bioshock is the kind of game you owe it to yourself to play just to get the great atmosphere and pretty graphics but don't expect a deep storyline or revolutionary gameplay because you won't find it here. It manages to stay afloat rather than sink under its own hype but on the other hand it doesn't surf the high waves of better games like System Shock 2, Deus Ex or Thief.