Basically just a big movie of Dracula being petty and vindictive. “You put up a ‘No Vampires Allowed’ sign on my house while I was sleeping, so now I’m going to kill you and turn your niece into a monster.” That sort of thing.
There’s lots of inexplicable stuff (Why is there no road to Dracula’s castle? How does he burn a body to nothing in the fireplace without everyone in the inn smelling it? Why is there a weird dungeon with Dracula in it just off the bakery?) and none of the vampire scenes are anything particularly special, but there are a surprising number of genuinely good and funny character moments.
I like how the rules that govern vampires keep changing in Hammer movies. In this one in order to kill Dracula you apparently have to impale him with something and then pray. If you don’t pray he’ll just writhe around like a character from War of the Monsters who got stuck through with a radio tower and then eventually pull it out and be cranky(er).