This just ain't a good movie.Go ahead; try and find a plot. Try and find some sort of underlying theme, or some sort of idea of the monster's motives, or method to its madness. You can't. From the time it's released from some sort of jade vase as a vapor to when it is finally defeated, it's a kind of generic monster that does whatever the writer and/or director needs it to do that moment. The movie is also hilariously dated.
As bad, no-budget horror movies go, though, it's done relatively well. With a simple goal of grossing the audience out, it does that. There's vomited worms, people eating dog entrails, and icky green monsters having sex with pretty young women. The movie careens haphazardly between these events like a pinball, its cast never seeming to understand what's going on but also never seeming to be terribly disturbed by it. Indeed, it's like they're not aware much of the time, until the plot requires it. This may be the single most arbitrary movie ever made.
At least it's enthusaistic. There's something kind of admirable about the way it just charges ahead with its nastiness, leaving plot details behind, like "we could explain this, but isn't the unknown scarier, anyway, and, besides, it would waste valuable time that could be spent revolting you."In that way, this Hong Kong horror movie is like its kung fu cousins, knowing which bits of the movie the audience responds to on a visceral level, and not wasting much time with the other stuff.