I think during the 80's, while Cronenberg and the like were showing their special effects skills, some daring Japanese directors were ready to show their might on the screen and it led to these films. All of them were put together to showcase nothing more than special effects with almost no story line whatsoever. Except this little gem!! I have to say, these films are definitely heavy on the gore, and they are way good at the special effects. They definitely caught me off guard when I saw them without knowing what I was sitting down to watch. But that's where it ends, special effects for gross out factors (which the Japanese do very well). But again, this one is a bit different than the others, so don't just write it off like perhaps "Flower of Flesh and Blood" or "Devil's Experiment".
First off, this has the artist element, as the crazy man who paints the scum and filth inside of a sewer would. And it has a very strange feeling almost from the get go. An almost bizarre art house quiet despair right from the get go. You can almost smell the rotting filth just by watching it. And that's exactly how I can explain this film, as if you watch an animal get hit by a car and watch it die, and subsequently rot to a bloody mess on the side of the road. But that's only an allegory to what the movie looks like, as the movie is perhaps an allegory to a deeper meaning.
While this film is certainly vile, and has loads of gross out factors from stem to stern, it has a certain humanity to it. Almost a beautiful love to it. And that is where this movie stands out from the others.
If you've seen the others and haven't seen this one, then definitely watch it. If you've wanted to see them, and haven't yet, definitely watch this one. If you like gross out gore cinema, then definitely watch this one. If you're weak in the stomach, then steer very far away from any of these films.