1000 Misspent Hours gives it -3 1/2 (yes, that's a negative!) stars, which puts it into their "so bad it's good" category, and says, "everybody who cares about movies in which guys in tacky monster suits menace half-naked girls needs to see Horrors of Spider Island". Million Monkey Theater has a detailed plot summary and screenshots and calls it "a fairly sleezy West German exploitation movie from the days when such things were sure-fire money makers, marketed to audiences lusting for some skin and sex without any sort of pesky plot getting in the way." Weird Wild Realm admits "many a fan of cheap & cheezy vintage horror has assessed it as of the "so bad it's good" category" but doesn't agree. HorrorNews.net has plot information and planty of screenshots and this:
there is an overall sense of unbelievable awe at the hokiness of it all that transcends the crappy building blocks and elevates the film, just ever so barely, to the level of fun bad movie making. In much the same way people stare morbidly at train or traffic accidents, this movie compels the viewer to keep watching, if only to see where the wreck is going to finally stop.