Incubus

In honor of William Shatner's birthday yesterday:

Incubus is a 1965 black and white horror film directed by Leslie Stevens (creator of The Outer Limits) and starring Shatner and Milos Milos (The Russians Are Coming, The Russians Are Coming). It is the second of only two movies ever filmed in Esperanto and is the first film to be released with subtitles in the language of its country of origin.

Part 1:

part 2, part 3, part 4, part 5, part 6, part 7, part 8

Moria calls it "a rather terrible and dull film" and says, "the representation of evil is rather laughably banal". DVDTalk begins by saying, "Everything about this picture is haunted and strange, from the way it was shot to the fates of its actors." Images Journal has some positive things to say:

Darkly powerful images run throughout the film, no small thanks to the stunning camera work by ... award-winning cinematographers.
...
Several of the performers shine despite the language barrier. ... However Shatner comes off as the most accomplished performer. He inhabits Marc with an easy grace, capturing both his light heart and nobility with a subtle performance...

but also notes:

Any discussion of Incubus would be incomplete without touching upon some of the bad luck (some would say the "curse") that has plagued the film for over thirty years.

It gets a 63% rating at Rotten Tomatoes.