Nice game, always good to see some relatively unexplored themes popping up.
Now, don't get fooled by the 7 endings. Two of them are the 'bad' endings. There is one for getting all the secrets. The other 4, the 'good' endings, are not directly linked to a specific scene, but rather to the achievements (which MIGHT need you to play a specific scene).
Let's move on to the criticism! (may contain some SPOILERS, and I'm gonna skip right past the bugs and spelling errors)
First of all, the graphics are so-so. The model in particular is quite badly shaped, in my opinion. The shoulders are too broad, the arms look weird, her waist is way too slim, and her breasts look plain fake. Add to that some weird spotty textures...
Secondly, the 'endings'. Now this may not be entirely the fault of the game, but still, when reading 7 endings I expected 7 different sex scenes or at least 7 variations of a scene. But there are only 2 such ending scenes, really.
Linking the endings to the achievements makes them particularly hard to find. I gave up trying to achieve the 3rd ending, even after decompiling the swf and searching through the code I still can't do it (if I remember correctly, it would trigger if you have the 6th (?) and 8th ('hot mouth') achievements, but not the 5th ('romantic') and 7th ('table something')). Even so, I know it won't give me any extra scene (and I got the ending link from the source anyway).
Might as well note that I think it's weird not to include the endings in the flash itself (even if you wanted to advertise or track gameplays you could do it in flash).
Thirdly, the secrets (!! spoilers ahead !!). Oh boy, secrets! My hope that these would simply be rare deviations in gameplay (say having bloodlust almost full at some key point) was shortlived. So was my hope that at least we'd get a mouseover hint. And finally, after going back to the source, the hope that they would at least all be kept in the vampire/graveyard theme ended as well. I mean 'a cupboard full of oatmeal', REALLY?! The second secret that doesn't make sense is on the map screen (even knowing that there is one there doesn't make it trivial...). The other 3 require some searching/random clicking but are at least in the right theme. Catch them all and you'll get a special ending! Not a bad premise, but at least keep the secrets somewhat logical.
Finally, to come to the gameplay a bit. It's 'ok', nothing new, nothing really bad, mainly just very linear. A point of annoyance though is that since it is required to replay the game many times is that I can't skip or accelerate certain stuff (the driving, sex scenes..).
But all in all I'll just keep it at that it's an 'ok' game (but short).
Edit:
One more thing, I have to question Leonizers taste if he calls Kristen Stewart "just sooo not - hot" (that's right, not just 'not hot', should we believe she's a cave troll, perhaps?). I'll leave this here to judge for yourself:
http://www.youtube.com/watch?v=SxBxqkMmzfI