There are a lot of faults with this film, particularly in comparison with Bakshi's later Lord of the Rings; the use of stock footage, narration over stills, awkward dialogue, inconsistent art and animation styles, and grotesque lapses of taste.
None of which matters. This is the fan-boy film par excellence, a tour-de-force of trippy creativity.
If you're an amateur animator yourself, you will find this movie inspiring. If like me you're old enough to remember fantasy before the polish and commercialism of CGI blockbusters, you'll appreciate the reminder that some people once made films for fun. Because they could.
If you enjoy the better amateur animations on YouTube, the parodies and pastiches that're exercising the next generation of movie-makers, you'll like this film. And if you like this film at all, you'll love it.