To be honest, running headlong into big daddies repeatedly and getting killed repeatedly put me off.
The main story is engaging, the moral dilemmas and set pieces all add to a sense of a living breathing city that has fallen into chaos. You can kill people, not kill people, get a robot to kill them instead, or on certain occasions let a big daddy do the job for you too. The story moves along nicely, it's twist on an alternate 1960 is every bit as polished as the alternate 1950s of the Fallout games, speaking of which keep your eyes open for special appearances by Vault Boy throughout. The story is told through audio journals left by the ever increasingly insane inhabitants of the once Utopian city and fill you in nicely on what happened and the characters involved in the downfall of the perfect world around them, a mixture of science and anarchy with a dash of alien invasion; or in some cases they just tug at your heart strings as you find out what happened to various characters, usually by stepping in a large patch of dried blood.
Now all this sounds immersive and to be honest fantastic, AND IT IS. The real problem I had with Bioshock was with it's main mechanic, the combat. On the face of it you can mix magical powers with some choice weaponry, and then you can mod the weaponry too, creating a nearly endless array of weapons with which to dispatch the lunatic denizens of Rapture, and to an extent it does. Until you discover that the creeps get tougher fast, they become almost immune to certain attack types and then you run into the issue of swapping hands from magic powers to weapons on the fly and of course not having the correct magic when you need it, the whole thing becomes a bit of a struggle, and not in the nice challenging kind of sense we all know and love.
Then there are the Big Daddies. These now iconic bad guys are like bulldozers on 2 legs and speed. Until you are close to the end of the game there will never be a point when a big daddy is an easy proposition, in fact, they just aren't, and this is where the worst part of the game comes to the fore. If you go up against a Big daddy and die, and you will die, you will then be resurrected at a "Vita-chamber", great! But now you are minus a ton of weapons and ammo and EVE and at only half life, and ALTHOUGH you have been resurrected and the big daddies health will remain at the level it was at when you died, meaning you can systematically wear the swine down; it is NOT fun to do so! After you have died a couple of times you will be left trying to kill the Big Daddy with a standard pistol and half your life, and when you do you will have to start building up all your stocks of ammo and EVE and curatives from the beginning just so you can go through the same thing with the next one, and this is made all the harder by the increasingly difficult to kill splicers I mentioned.
It is such a shame that in creating such a vibrant game world they also created one of the most annoying game dynamics I have ever come across. If you think you can stand dying a lot then by all means give the wonders of rapture a try. If you would prefer a game that has a slightly more sensible death and retry system, just about any other game will do!