Well it wasn’t that bad, however I feel Simon Pegg would have done it awesomely :)
Also they missed a trick with the lines, when the Ex has just been killed there was a pause which should have contained this dialogue according to the script writers playbook:
Jimmy: How’d you know she was a vampire?
Flech: I didn’t.
Barring that they had all the good bits of the standard horror/comedy playbook as well as some interesting twists, the swearing priest was particularly fantastic :)
Most interestingly the theme tune seemed to include the main riff from the Monster Mash as well, which brought back fond memories of some speccy game or other.