^Not sure if that is what you were getting at but I agree that the movie's first priority is to capture the feel of the games and make more direction references (like storyline references and characters to a certain extent). It doesn't have to resemble one specific game, but the basic foundation should be there at least. And obviously the movie should share the same concept of that of the games. They shouldn't make it a Bram Stoker's Dracula rip-off, like Anderson's initial idea.
I am trying to say, that if it somehow, despite all odds ends up as just a good movie, with little resemblance to the Castlevania - its OK, since so far there were only handful examples of translating video games to movies, that ended more or less decently. At least there will be good movie about vampire hunters with the name "Castlevania" and even, if it will be hardly related to the games, it is still promotion that can inpire some people to get familliar with the series.
Though this director certainly doesn't give me a lot of hope for something closely resembling CV, not after RE series with Mary Sue for a main character. I will laugh Out Loud, if the main hero of the movie will be Sonia Belmont portrayed by...
I am personally not even sure what kind of Castylevania movie I want to see - there is too much material and most of it could turn awesome in the right hands. The closest thing for a Castlevania movie was Van Hellsing, but that was mish-mash, that ended rather horribly.