A solid game, a must play in fact. However, only worth playing once.
It's a solid game, and an engrossing experience certainly. It's atmosphere is almost unmatched. The idea is intriguing, the world is nicely realized. However - It's no where near as "innovative" as it was billed. The enemy AI doesn't do anything all that remarkable. The "choices" that we were supposed to have don't have that much of an impact on the game all things considered. Sure a few sections change slightly but you don't affect any drastic or even quantifiable change to the actual gameplay. You'll get a different ending movie, and some alternate lines of dialog here and there. Not much else.
The reviews, previews, and interviews made it seem as though you would practically mold the world around. You most certainly do not. The reviews acted as if it had almost unlimited re-playability. I had utterly NO desire to play the game again. Despite this, I did start a new game on hard and played for a fair amount of time. The game wasn't really harder so much as it just took longer to kill your enemies. I really wish that I had played through the first time on hard just to get that achievement. Part of the problem with the difficulty is that you re-spawn when you die with no consequence other than a slight inconvenience of distance to where you were. This completely removes any of the tension usually associated with FPS or hell even action/combat games in general.
Some of you will probably say something to the effect of "With all of the plasmids and tonics available to you, you end up with a lot of choices". This is somewhat true. But choices in combat aren't all that innovative. Every FPS gives you choices in combat, what weapon you use, where you attack from, who you attack first, when you attack etc. and while BioShock does have more options on the surface, it's really not quite as expansive as it seems. All you really need to survive is Telekinesis, Ignite, Electro-bolt and maybe the Plasmid that Freezes(name escapes me) . I got some nice Wrench damage boost tonics, attack and movement speed tonics, as well as a tonic that made my Wrench have a chance of freezing my opponent. I found that in a game filled with weapons that can be altered in a fairly decent number of way, that I used the starting melee weapon almost exclusively. In fact I wished that I could upgrade the Wrench at the Power to the People machine instead of the other guns.
And there is the story itself. (I won't spoil it here, even though most people have probably played the game or at least know the story) It's not as epic as I was led to believe. It's possible that certain aspects of the game were meant as a sort of commentary on the state of FPS games in general. Despite this, it sticks just as close to those conventions as most other games do. Claiming to be beyond those conventions or pointing them out only works when the game itself does not use those very conventions. And you spend the entire game with disembodied voices guiding you through everything. Again I was given the impression that I would be more or less going solo throughout the game. I was not.
All told this game is still a definite must play, but it really isn't worth owning. Nor is it really worth all of the praise it has received.
But then, that's just my opinion.