This is the silliest, most enjoyable, film I have seen in a long while. The tongue-in-cheek gothic setting is reminiscent of a Muppet Show sketch with its bad Baronets, fake cob-webs, goody-goody heroine, dancing ghosts:- it even has Vincent Price as the guest star! The unlikely storyline is very easy to follow and the songs are catchy and not too pompous. The younger members of our household enjoyed it too - they said it reminded them of a Tim Burton film.
If you come to this looking to find fault, I'm sure you'll find plenty to criticise - the acting is pantomime, the sets rather basic, and some of the video effects - such as a heart shape framing two lovers for a duet - look like a second-rate you-tube video. In addition, Keith Michell (in his 50's) looks a little old as the bashful young Robin Oakapple, but not as old as his 'younger brother' (the 71 year old Vincent Price!).
But I think this is missing the point. If you want gritty realism watch Trainspotting or something like that. This is not meant to be taken seriously, it is meant to be frivolous nonsense - and it made me laugh. It would be the perfect show to have on the television on Christmas afternoon - I'm surprised that I could not find any other film versions of this Gilbert and Sullivan masterpiece apart from an animated version
Ruddigore / Tales from Hoffnung [DVD] - perhaps if Tim Burton is reading this he might give it a go; there's even a role for a crazy mad woman that would suit Helena Bonham Carter perfectly.
This DVD, which includes a libretto (lyric book), is also included in the complete box set
Gilbert and Sullivan (1982) [DVD], and it probably makes more sense, if you like this sort of thing, to invest in the set.