If "Henry" were poorly made it would merely be categorized as another gruesome slasher flick.

But because this low-budget, independent and long-neglected film (it was completed in 1986) boasts superb performances and solid direction, as well as a unique approach, it's not easy to dismiss.

You may have read about "Henry," subtitled "Portrait of a Serial Killer," in the national press, where it has become something of a cause celebre with regard to the movie rating system. "Henry" received an X rating for violence. The producers rejected the X and the film is being released without a rating.

But does "Henry" deserve an X?

True, it is gruesome, gory and shocking. But it really isn't any more gruesome, gory or shocking than any other R-rated horror film — not to mention so-called action-thrillers like "Total Recall" or "RoboCop 2."

The problem here is apparently that "Henry" means to treat its subject realistically, and as such it is disturbing to watch and unsettling to think about.

If the killings depicted in this film were as gleeful as those in the aforementioned big-budget mainstream films, perhaps it would easily rate an R, since the actual content, the graphic depictions of death and mayhem, are no worse than any other R-rated film I've seen. If that's the case there is no small irony in butchery-as-fun being perceived as more palatable than butchery-as-repulsive.

Director/co-writer John McNaughton has serious matters on his mind. He wants to depict real-life horror, random killings that have no rhyme or reason. Not those performed by the kind of killers that have dominated horror films for the past decade — this is no faceless hulk in a hockey mask who represents adult authority as he chops up promiscuous teens. The title character here is a flesh-and-blood human being who can be charming and provide pleasant company, but who gets his private thrills from taking human lives without his conscience getting in the way.

Further, McNaughton uses a gritty, documentary-style approach that heightens the realism and makes it all the more frightening. If this movie were in black and white, which automatically adds tension to a movie, I don't know if I could have made it all the way through.

The story, which a prologue tells us is based on the confession of an actual serial killer, focuses on the title character Henry (played very convincingly by Michael Rooker, also in the current "Days of Thunder"), who kills for the thrill.

But Henry is no dummy. He has his technique down to a science. As he explains about halfway through the film, while initiating his roommate Otis (Tom Towles) in the ritual of murder, he kills randomly, he kills only people who have never seen him before and he uses different methods and weapons with each killing. Then, after a short time, he moves on.

This, of course, is to prevent police from catching on to him — and the audience becomes chillingly aware early on that this guy probably won't be caught. Do such people really exist? Anyone who reads a newspaper or watches the news knows they do. Whether we want to see a movie about them is something else.

Henry is painted as a vulnerable human being and the first half of the film has the audience feeling some pity for him. But McNaughton is deliberately vague as Henry reveals information about himself to the audience, and gradually pity gives way to fear. One of the film's best scenes has Henry explaining to his roommate's sister Becky (Tracy Arnold) how he killed his mother — but he keeps changing the weapon as he tells the story. Henry has been committing murders for so long they are all beginning to run together.

McNaughton builds the terror slowly, first by merely showing us Henry's victims in the aftermath of violence, then letting us in on the violent acts. The first killing we witness is an act of aggression against an obnoxious character, so naturally, after all our training in "Death Wish" movies, we feel the guy had it coming.

But then comes the clincher, as we see Henry and Otis slaughter an entire family — father, mother and son — as seen through the eye of a video camera. One long scene without an edit, given an extra level of tension when the camera is dropped and we see the rest of the scene from the floor, as if we are also a victim.

But the real shock is yet to come: As the scene reaches its conclusion we realize that Henry and Otis are watching the video at home, like some perverted — or more perverted — episode of "America's Funniest Home Videos."

That is without question the film's most uncomfortable moment and reportedly prompts members of the audience to walk out during every showing.

Whether that's entertainment is debatable, of course, and McNaughton is not above some unnecessary exploitation, whether it be graphic rape scenes, gory makeup or cheap jokes. Those elements do occasionally bring the film down to the level of a cheap horror movie.

On the whole, however, McNaughton's film is as disturbing as he intended.

Whether you interpret that as a recommendation is a matter of personal taste.

As for me . . . well, let's just say I have some admiration for this film. But I also have no desire ever to see it again.

"Henry: Portrait of a Serial Killer" is not rated, but contains graphic violence and gore, sex, nudity and profanity.