I rented this game because several sources consider it to be the best game of 2007. That was pretty much all I knew about Bioshock before it arrived in my mailbox.
This review may be a little premature -- I'm only about three levels in -- but so far I'm delighted with it.
It's creepy, gripping, and it sticks with you when you're not playing it.
I especially enjoy the freedom a player has to find unique ways to beat opponents and complete goals. You get a chance to be creative, and you won't find yourself relying on one specific ammo type to beat baddies. Out of grenades? Lure a foe into a puddle and electrocute the SOB. Out of bullets? Hack the turrets into your favor and let them do the shooting. There are lots of ways to succeed here.
The fright factor in this game is way under rated. You never know when the lights may suddenly go out, only to turn back on to unveil a hook-handed slicer standing immediately in front of you, grinning.
The ambiance is spot-on, and the art deco motif is original and authentic.
No game is perfect. Perhaps the combat will get redundant, and the levels are certainly linear, but there are enough little puzzles (including the rewarding hack system) to keep things interesting.
I'm finding this game to be completely enthralling, and I recommend it whole-heartedly.
Bioshock is easily one of the best games I have ever played. This is the whole package. It's got a great story, an awesome atmosphere, and the gameplay is unique enough that it doesn't come across as just another FPS.