This is a rather low-budget flick, and it's drowning in unnecessary melodrama, but it's not altogether a terrible movie. Definitely below average, though.
Having a main character with alcoholism was interesting, and adding a little something special to her character (while also adding drama that was a bit much). It's this drama that holds the movie back, though, and it's not just on the main character. The whole small subplot about the husband's troubles at work strike me as entirely unnecessary, and though the conclusion to that was sort of funny, it didn't really add much to the movie.
The main actress, Kory Clark, did decent playing a slightly more complex character than you might expect. Given that this was her only role in anything, I'd say she did a decent job. Aldo Ray was a genial presence, despite his rough background, and made the movie just a bit better by his pretty solid performance.
For a slasher, though, the main problem this movie has is it's rather noticeable lack of kills, and when there are kills, there's not much in the way of gore, or, more troubling, suspense. Also, while I sort of liked the route they went with who the killer turned out to be, it felt sort of soulless, as though it was just superficial and lacking something. Still, it tried, I'll give it that.
Dark Sanity isn't a terrible film, but there's almost nothing here, aside from Ray's presence, that really stands out one way or the other. Definitely on the lower-end of slashers from the early 80's, I'd recommend that you pass on this, unless something about it seems to tickle your fancy.