The guys over at
1up have managed to get their hands on an early playable version of Bioshock, and have posted their experiences on their site. Be forewarned spoilers are a plenty as they've really posted a play by play commentary for the first few hours of the game. Among other things 1up says that Bioshock, despite being able to have special powers, is a shooter first and foremost. They also go on to detail how crazy and chaotic fighting a Big Daddy really is.