Well is there anything to do in Bioshock other than story mode ?
I'm thinking about buying it but it's currently 50$ so I'm asking if it's worth it or should I just wait for it to lower down .. ?
It's a story-based, singleplayer game only. Well worth the money for the experience even so, and Levine has talked about downloads offering extra content.
However, you should play the demo first to make sure you can run it, that you don't have chronic tech probs, that you like the style, etc...
Definitely. I've not heard anyone complain about the story. The backstory of the city is fleshed out in audio diaries and they contain some of the best voice acting I've ever heard. Then the dynamic story of your character's own situation gets more interesting as you progress.