The correct title and year of release of this film are shrouded in confusion, partly due to the various titles used in worldwide release and the fact that TCM has aired both the 1966 and this 1976 version, which is an adaptation of the 1966 version (which sounds superior to this one).
What we do know is that the film is adapted from the comedic ballet choreographed by Arthur Saint-Leon to the music of Leo Delibes, which was first performed in 1870. "The Mysterious House of Dr. C", as it is titled here, is a Spanish production.
In any event, the film is a non-live performance of a ballet set on a soundstage in Spain. It tells the story of a mechanical doll maker who is rather cantankerous and who likes to interfere in the lives of the townspeople. Swanhilda is a young woman involved with Franz, who becomes enchanted by one of Coppelius' dolls, named Coppelia. The story revolves around a festival in the small town and the romantic machinations that involve the main characters.
The ballet style is very classical and, I fear, some viewers might find it too static. Some scenes involve one of two dancers being watched by the ensemble. The movement is classical in the sense that it features posings or posturings. Much of the dance is folk-inspired.
The film includes voiceovers, sometimes in poetic form, like the reading of a story. It sometimes includes miming by the dancers to the voiced reading of their sentiments. It also includes animation. It's the kind of production that should interest a young child, but it might be too long or too mature for that audience. Those interested in ballet may find it too slow, with lots of standing around.
Dr. C is a bizarre character who is presented with little insight into his motivations, but he does recall other sinister characters in ballet, like Drosselmeyer in "The Nutcracker".
One would probably do better to watch the 1966 film version.