I know, the first impression comes months after the release of the game, one lauded for being one of the greatest games of all time. If it means anything, I'm ashamed that I didn't pick it up on release day. This game had me shivering with excitement just minutes in. The atmosphere is what truly makes this game. You swim past your plane as it's visibly sinking Titanic-style into the ocean, only to walk into one of the most ominous welcome rooms ever seen. And of course, the initial view of the city of Rapture is jaw-dropping as well.
Obviously I'm not very far into the game (still looking for my radio friend's family in the medical section), seeing as this is a first impression. However, I'm already very impressed with the environment and combat. The game is set in the 1960s, and music from the time period plays through speakers as you walk through the halls past neon-lit shops. It really has to be experienced firsthand, or you won't understand the feeling you get from it. As far as the combat goes, it's very unique. You have a limited supply of ammo, and your EVE (think mana) runs out quickly from using spells, but at the same time, you never really feel underpowered. There's just enough of a shortage to keep you conservative, but not enough to make situations seem impossible. Now if you'll excuse me (and this poorly-planned, hastily-written blog), I'm off to Rapture.

Dreski83
I loved Bioshock simply because it was more than simple shooter. Atmosphere is why we play games I would imagine, so why not add a little extra focus on that important aspect. And they did just that with Bio... kind of gets me excited about playing all over again