I think that how one rates and reacts to this movie has to do with the following:
Are you familiar with the oeuvre of director Bill Rebane? And if you are, do you consider (or admit) that you are a fan?
If you're not familiar with Mr. Rebane's other movies and just came to this because you either wanted to see Tiny Tim in a slasher movie, or were just looking for a weird, idiosyncratic take on the 80's slasher genre, then you may well enjoy this film. It's offbeat and has some twists and plot contrivances that you don't find in more mainstream films.
However, if you are one of the select few who have enjoyed/endured Rebane "masterpieces" such as "Invasion From Inner Earth" aka "They", "The Game" aka "The Cold", "The Alpha Incident", "Rana: The Legend of Shadow Lake", then you may be as disappointed as I was after watching Blood Harvest.
Yes, it has some of the traits we have come to expect from other Rebane efforts...the odd characters, the sense of local color supplied by regional film-making, the juxtaposition of high drama with a sense of detachment provided via plot deficiencies and wooden performances.
But in the end there is something missing...whereas previous films by the director seemed to carve out their own peculiar identity through a sort of studied ennui, innocence, and single minded dedication to whatever peculiar sense of inspiration birthed the ideas that drove him to create, in Blood Harvest it seems that Rebane was content to be more follower than leader.
Tiny Tim is the standout actor here with most of the remainder of the cast unremarkable to wooden. While there is a decent quotient of gore and gratuitous nudity to be found, it just seems like padding and standard genre tropes.
While this may be an atypical and somewhat satisfying outlier for 80's slasher fans, this lacks the kind of Thorazine "magic" that the rest of the auteur's filmography contains.
At least for me.