Wow, this game is great. I meant to play it a while ago but I never got around to it. For those of you interested in getting it you can subscribe to IGN for a year (priced at $19.99) and get the game for free with it, or buy it off Steam for the same price but with no IGN subscription.
Basically, for fans of Deus Ex this game has a ton of similarities. I'd say I'm maybe 25% of the way through the game right now and while it isn't quite as good as the original Deus Ex, it is MUCH better than the sequel to Deus Ex (Invisible War). This is definitely a fantastic game.
You choose to be a male or female out of a number of different vampire clans. Depending on what clan you choose they have inherent benefits and drawbacks. I just picked the one that looked and sounded coolest. You have a ton of different skills that are raised via experience points (just like Deus Ex) though the stats are actually more complicated, similar to System Shock 2 where you have a lot more to choose from. You get experience points for doing the main quests as well as the many side quests. It has huge dialog trees just like Deus Ex where your decisions affect what you're doing in the game. It is built on Valve's Source engine (Half-Life 2) so it looks and runs pretty well. You definitely have a lot of choices like Deus Ex, multiple paths to take, a ton of optional content, you can be stealth, direct, etc. I'm generally not too into vampires but if you are this game is even better since there is tons of storyline and shit revolving around the vampires. Your abilities (which depend on what kind of vampire you are) use blood every time you cast one so you need to feed off of people (but don't get caught). I invested in the seduction skill so you can go to night clubs and feed in public if you seduce them, which makes people think you're just making out or something so you get away with it.
The game is really bad ass. There doesn't seem to be much ammo for the guns so melee (at this point) seems much more viable since it does just as much damage and doesn't take ammo. Deus Ex had pretty vanilla melee, you didn't really do much. It's a little bit different in this game, you can perform stealth kills, and when you are in a regular battle you just kind of mash on the button to do combos and it's almost like a hack and slash game. It's a little better than what Deus Ex had for melee but not by a lot. You can play in first or third person. I play in first person except when fighting with melee, in which you are required to be in the third person, I would prefer it that way anyway though.
The guns (the few times I've used them) work similar to Deus Ex. Your accuracy is pretty bad until you raise your firearms skill, so I haven't used it much yet due to limited ammo. For the price you really can't beat this game, if you're a fan of Deus Ex definitely pick this up, it's low priced, fun, and I love all the great dialog options. Honestly at times it feels like you are playing Deus Ex, this game has a ton of similarities and even looks like it sometimes. This game is a real treat and I'm savoring every moment.
Oh, and it has a scary ass level in it...I nearly shit my pants, but what's new? Also, be sure and get one of the two patches available. The developers went out of business before they could patch it up completely properly so fans have made a massive patch for this game, you can find them both on the Wikipedia page.
There is one patch that just fixes everything returning it to the way the developers intended, while the other is a massive patch that includes removed content the developers left on the disk (voice overs, quests, etc.). So one patch is the regular game working flawlessly, while the other is almost like a "Director's Cut". I'm going to save the "Director's Cut" for my second play through.