Bioshock gives you an overall feel of everything you want in a shooter game!
The Negative in the game are the 'Vita Chambers.' Vita Chambers revive the players where they died from without any penalties. This leaves the game too easy to beat when the player is revived with ALL items started with. This can make the player reckless at playing the game without fear of suffering any significant losses. This takes away from the challenge of strategy.
The Graphics are simply amazing. The detail and the sound of Bioshock makes you feel in the game.
Difficulty is just right. They present the setting of Easy, Medium, and Hard. Which can be set at the players likings...