I recently (finally!) got my hands on my copy of Bioshock 2, and I can't say that I am anything but pleased. After having played the first several hours of the game, the story is starting to ramp up, and the gameplay has distinctly differentiated itself from the gameplay of the original. The game is like Bioshock, but improved in nearly every way that I can remember people complaining about. There are unexpected perks of being a Big Daddy, more ADAM, more powers, more guns, more choices. It's a fantastic almost sandbox combat system.
So why all the hate concerning it's familiarity to the original? Isn't that what a sequel is supposed to be? I was under the impression that a game's sequel is an extension of the energy that existed after the original's release and served, when done correctly, to deliver more of what people loved from the first. This fits in all media forms. I'm not going to read a new Harry Potter novel and expect that J.K. Rowling's writing style has sudden transformed into that of J.R.R Tolkien. If I'm reading a novel by Rowling, I expect a novel by Rowling. If it's Lord of the Rings Part III, I don't expect that there should be a completely new cast of characters and events. Gandalf and Frodo aren't going to profess their love for each other and go on a series of moonlit strolls through the park. That's just absurd. Ghostbusters 2 was very similar to the first Ghostbusters.
This is true of video games too. Look at Halo. That's one of the most successful series in recent history. Why did Halo 3 do so well? Lots of people will argue that it's an improved version of Halo 2. Or Gears of War 2. It's fundamentally a massively improved version of the first; they fixed a lot of problems people had with the original. People who liked the first, generally liked the second. Why did Halo ODST do relatively poorly in comparison with Halo 2 and 3? It's because it varied pretty wildly from its namesake and provided a gameplay style that Halo fans didn't expect.
So why would anyone expect Bioshock 2 to be a complete departure from Bioshock: especially when the first Bioshock was such an incredible title? Why are people complaining that they took the original game, mixed some things up by letting you play as a Big Daddy who is already familiar with the world of Rapture, and fixing little annoying things like the hacking all the while improving the combat immensely? It doesn't make sense to me that people think that Bioshock 2 is not worth your money because it's very similar to the first when the same people go out and spend $60 on Modern Warfare 2, which takes what COD4 did, and makes tons of unnecessary "improvements" and additions that nobody asked for, and make the game less fun. It was always my impression that sequels are supposed to deliver more of the source material in a compelling manner.
Like several games before it, namely Gears 2 and Forza 3, I can name a ton of things that Bioshock 2 does better than the original. At the same time, I can name a ton of things that it keeps. If I wanted something different than Bioshock, I would have bought something that was NOT Bioshock's sequel. Don't listen to the critics. Is Bioshock 2 perfect? Absolutely not. Is it a fantastic game that simultaneously delivers an authentic and familiar experience in Rapture while improving on the weaknesses of the first and adding several great improvements and twists on the gameplay? Absolutely.