First, I am writing this review to clarify other reviews.
It is a Windows Live game, which requires to login to play the game, unless you start without Windows Live login and then you do not keep the achievements. So..what is the problem? if you want achievements you need to login, otherwise don't. Windows Live does not require a credit card, and you can use any Hotmail account so it should not be a problem.
As for activation... People, grow up. Xbox360 and PS3 won't let you play a game if your console is not up to date, and it tracks your games too. The DRM is built into the console, so in overall PC has had it pretty good for DRM. I am an IT person and I never re-install Windows, even when I make huge hardware changes like moving my hard drive from a Core 2 Duo to a Core i7. I don't particularly like DRM for the fact that 15 years from now I might want to install the game and it might not activate, but otherwise it is OK, and it is here to stay.
As for the graphics....Reality check, 90% of big blockbuster games are develop for console and then ported to PC. Game does run better with Direct X than 9 from XP.
Game play compared to first game...People, be fair when comparing to the first game. This is an excellent addition to Bioshock universe. It expands the story from the first game, while adding elements of its own.
Graphics: they are better than other ports I have played. It still managed to stress my 8800GT SLI setup, which not a lot of games do. It has better graphics than the first one, but remember it is in the same place. So expecting the same locations, this are a little better.
Game play: you play as the Big Daddy, which is fun. Techniques change, and it is setup so you know when big battles will happen so you can prepare the ground and use the environment to your advantage. I think it is better than the first game.
Story: I haven't finish the game yet, but I did like the story of the first one better, however this does not diminish from the story at all. If the original story was a 10, this is a 9.
Length: it is average, however it can be longer or shorter depending on your gaming style. If you go only for the main story plot, it can be a short game, however if you explore all areas it is quite large, probably larger than the previous Bioshock.
Special Edition: This is a nice package. I collect games, and this game brings the soundtrack in CD and record, to give the feeling of the 50's. The usual art book, and a really nice package.
At the current price this is a super value game. If you know someone that played Bioshock 1 there can be errors buying this game