The concept revolves around the idea of some kind of hidden evil force that resonates inside the spiral pattern. The Japanese word “uzumaki” literally means “spiral” in English. Japanese audiences may have identified with this form of horror more so than other audiences, because from (what I understand) of their culture, there is a tendency in their folklore to put extreme emphasis' on non-descript objects. While I, personally, have no such precursor, I do love the imagery of the spiral pattern, as throughout my youth, Tim Burton's cinema and "The Cabinet of Dr. Caligari" shared a spiral motif of sorts, and were very influential to me.
"Uzumaki" uses this spiral villain to probably its utmost possible effect. At first, it seems an obscure design, but the film manages to find spirals in places that a normal person doesn't think about. It is this very acute observation where "Uzumaki" excels. Its characters realize how dangerous the spiral is, and in that realization, they begin to find it everywhere. It is a recognizable mania that ensues, for the viewer can instantly relate to every finding, and if they are at all affected by the movie, will begin to see things around them in a different light. Fusilli can all of the sudden have dark subtext to its existence.
Where "Uzumaki" fails, is providing adequate payoff for its suspense. Having no to little payoff is generally acceptable, but when a character finally reveals what is at the end of that hallway, instead of something scary, it's usually kind of laughable. The entire film seems structured this way. I don't mind that the evil is never really explained, but when you are designing a series of escalating suspense scenes, the horror in those scenes should escalate as well; not be equally or less silly than the last. I spent most of the movie laughing at what the filmmakers assumed was creepy, and I don't think I was entirely supposed to.
That's not to say I didn't enjoy "Uzumaki", or that the silliness wasn't intentional. In some cases, I assume it had to have been. But Higuchinsky (the director) films everything in drab blues and greens, and seems to make a genuine attempt to scare. I don't really care that I wasn't scared; I still had a good time, and I will still recommend "Uzumaki" even though I can't imagine that it achieves the desired effect of its director.