Ugh.
I hate to be the downer here, since everyone else seems to love this game, but I have a few issues with it.
I played the first game, and I thought that the game-play was a bit too simplistic for a puzzler. It made up for it with atmosphere and great story-telling, though. I don't feel like this game has either, mainly because the sudden appearance of vampires. Things get a lot less interesting and a lot more camp. The game also relies on jump-out scares, which is a disappointment. I'll admit, the first time a vampire came out of an air vent I jumped, and high. It only really works the first couple of times, though, and it quickly got old. Once I got to the final fight, It was impossible to take the game seriously.
As for puzzle solving, the same problem has carried over from the first game: It's more like one of those "Eye Spy" books than a puzzler. You never have to figure out for yourself what it is you have to do, the game just tells you outright. All you have to do is look for blood vials and passwords.
Anyway, don't let me ruin your fun. You might still like the game, if you don't mind that it has vampires now.