In recent interviews Kevin Levine has stated that Bioshock was never meant to be the success it was. Speaking from past games he had developed which were critically acclaimed but never sold well, he expected Bioshock to suffer the same fate. In fact, the whole team did. So, the fact that Bioshock made it big is all the more astounding.
Bioshock was one of the best games released in the early life of the Xbox 360 and remains today one of the most outstanding first person action games on the system. So did we really need Bioshock 2? When the game was announced there were fears that it was a cash-in and the universe didn't support it. Having played the game now, it is clear that the Bioshock universe can go far beyond what we ever imagined.