When considering the meager merits of the bone-snapping, blood-splattered "Ninja Assassin," it's best to remember the words of John Goodman's PC-challenged character in "The Big Lebowski": "The man in the black pajamas, Dude. Worthy ... adversary."

The makers of "Ninja Assassin" want to make those words real and rescue the ninja from the province of turtles. They want you to revere the ninja. A frightened old man at the beginning of the movie can't even bring himself to utter the word "ninja." That's how much respect the old-timer has for "the man in the black pajamas."

"Ninja Assassin," though, has a funny way paying its respects to the sword-wielding saboteurs. Director James McTeigue ("V for Vendetta") and his producing partners, Larry and Andy Wachowski ("The Matrix"), are clearly more interested in spraying geysers of digital blood than in establishing the ninja as a foe to be taken seriously. There hasn't been this much limb-severing in a movie since the Black Knight's "flesh wound" in "Monty Python and the Holy Grail."

The death-dealers in "Ninja Assassin" belong to the Ozunu Clan, a secret society that, for the past thousand years, has supplied killers to any government that has a "hundred pounds of gold." Their artery-severing antics have come to the attention of beautiful Europol agent Mika Coretti (Naomie Harris), which is bad news for her, since they don't believe in advertising.

Fortunately for Mika, the clan's deadliest assassin, the brooding Raizo (Korean pop star Rain), has decided to betray his brothers after watching them butcher the love of his life. Raizo somehow finds Mika in Berlin, and the two dodge flying blades and other pointy weapons on their way to a final confrontation with the clan's raspy-voiced father figure, Ozunu (Sho Kosugi).

To work, "Ninja Assassin" needn't have equated a seriousness of purpose with self-seriousness. But it's clear from its opening round of mayhem and decapitations that McTeigue simply wants to satiate fanboys' blood lust in the most simple-minded fashion possible. That first scene is a doozy with fountains of arterial spray rivaling the nightly show at the Bellagio.

However, since the ninjas only come out when it's dark, most of the movie's fight scenes are low on both visibility and excitement. The murky dimness provides a nice contrast with the bright red blood spraying everywhere, but it doesn't help much in tallying the body count. The movie loses style points, too, for variety (the fights are almost exclusively shot in close-up) and for its fumbling, quick-cut editing.

As for Rain, the movie addresses the problem with an in-joke that's a little too on-the-nose to be funny. "He doesn't look like a killing machine to me," a rival says. "He looks like he belongs in a boy band." In other words, not exactly a worthy adversary.