I just saw it. It was hardly worthy of a raspberry. It was pretty and entertaining, albeit with cliched themes (that seemed overly "Japanised", probably not in the source material) of eternal life, death, darkness and light etc. At one point someone says "You can't have light without darkness". Yawn. It's as violent as Mononoke, but it isn't similar. There is no war in the film, and most of the scene star only a few of the six main characters, which makes it a very quiet, almost mysterious film.
There were a few scenes that seemed poorly edited, with unexpected jumps and a few confusing perspectives (doesn't make it clear where the characters are, or where they're facing), clearly showing Goro's inexperience with the basics, but this doesn't spoil the film. The music was good quality, and gave the film a good backbone, though the singing scene was too long, some people in the (small) audience were laughing by the time the chorus was sung for the last time.
Despite what the Cineworld site said, the English dub was shown. Willem Defoe's voice is excellently creepy and perfectly fits the softly spoken feminine villian, which was strange, as most of his roles are anything but feminine. Because of that, I didn't even recognise his voice at first. Timothy Dalton's voice was also good and fitting the character. The kids are a bit annoying, especially the girl Therru, who often sounds like she's clearly reading a script. Arren's voice actor fell to the common problem of not being able to decide whether to be English or American. I noticed the dub was done by the usual Disney crew (Lasseter etc.) which is strange, considering they have two years to wait until they can release it.
I think I should end this by saying that if you don't expect Miyazaki standards, you'd enjoy it. It is an entertaining film, with exellent visuals, and as seeing anime in the cinema is rare, you should go along.