Does the presence of vampires automatically make a film a horror movie? This used to be an interesting question back in the day, you know, before it could be answered with two simple words: "Duh, Twilight." As horror fans, I think we've definitively kicked that series the hell out of our genre and sent it home with its fluffy werewolf tail between its legs. But what to make of Blood and Roses? After all, it is the film's tragic and romantic elements that drive it, and like in Twilight, the supernatural part is merely a vehicle used to explore other themes.
The difference, I suppose is that Twilight is a money-making machine rushed into production to cash in on the popularity of the latest (semi)literary phenomenon, while Blood and Roses is an artfully-made film based on a classic gothic tale from 1872. Basically, we want Blood and Roses included in our genre because it doesn't suck.
The best thing about Blood and Roses is its original take on the vampire mythos. Millarca is not your garden-variety drain 'em and leave 'em bloodsucker. When we first encounter her, she is no more than a voice in Carmilla's head. Right away, this sets up the audience to question whether this is a case of supernatural influence or some sort of psychotic break with reality. When Millarca appears to Carmilla, the audience never sees the vampire, only Carmilla's reaction. In fact, the whole film is set up to screw with the audience's sense of reality. My only complaint here is that in the end, the voice-over narration spells everything out explicitly, denying the audience the pleasure of piecing it together themselves.