Grade: C+

Will the real Guillermo del Toro please stand up? On the one hand, there’s the director of highly personal, dreamily mesmerizing art films like “The Devil’s Backbone” and “Pan’s Labyrinth.” On the other, there’s the permanently adolescent, creature-obsessed bad boy of unabashed popcorn flicks like “Mimic,” “Blade II” and, of course, “Hellboy,” his splashily invigorating 2004 adaptation of Mike Mignola’s flamboyant comic series. Visually the latter del Toro outdoes himself with this sequel, which gives his eye for gloomy beauty, his love for intricate mechanisms and his delight in creepy critters animated in Harryhausen style full rein. Unhappily, it’s all tied to a story that only intermittently captures the sense of goofy, off-the-wall fun that marked the first film.

That’s because this time around del Toro and Mignola have larded their screenplay with too much “serious” stuff about horned hero Hellboy’s (Ron Perlman) feelings of alienation from humanity, his stormy relationship with the pyrokinetic beauty Liz (Selma Blair), and his prospects of parenthood, as well as a doomed romantic entanglement for super-intelligent gill-man Abe Sapien (Doug Jones, this time around doing his own voice work instead of being dubbed by David Hyde Pierce). The outsider theme has worked wonderfully with some cinematic superheroes, like Superman or Spider-Man, but though the point about the pain of being different is worth making, here it comes across as leaden. The earlier picture raised the same issue, but less clumsily, and there too the attraction between Hellboy and Liz hadn’t yet turned into a Ralph-and-Alice kind of marriage, as now. As for the paternity subplot, it does bring one benefit—an amusing sequence in which the red-skinned demon protects a baby while fighting a giant plant (a homage, presumably, to the famous scene in John Woo’s “Hard-Boiled”—and reminiscent of the moment in the original when Hellboy is given romantic advice by a young boy). But otherwise it’s simultaneously over-cute and heavy-handed. And Abe’s romance never takes wing.

All the concern for such matters also means that the script skimps on the larger plot, which has to do with Nuada (Luke Goss), the prince of a magical race of beings whose father long ago reached a truce with humans and took his people underground. Nuada, a martial-arts whiz, is determined to break the truce and conquer the world with the aid of a golden army of invincible warriors who have been slumbering since the truce was signed. But to do that he needs to accumulate the three parts of an ancient crown—one that’s being auctioned off, another worn by his father, and the third in the possession of his twin sister Nuala (Anna Walton), who opposes his ambitions and comes under the protection of Hellboy and his government-sponsored crew of very special agents. All this is happening while Hellboy not only continues to bicker with the officious FBI guy (Jeffrey Tambor) in charge of the underground operation but must come to terms with a new boss, Johann Krauss, a gaseous entity encased in a protective suit (he’s voiced by Seth MacFarlane in a terrible German accent but actually acted by two guys—John Alexander and James Dodd—doing Darth Vader one better, though only in a numerical sense).

This slender scenario, much less complicated and frankly less imaginative than in the first picture, does allow for a string of action sequences—the first set in an auction house, another in the “bazaar of the trolls” and the street outside it, a third in the headquarters of the Bureau of Paranormal Research and Defense and the last in the Irish caverns where the golden horde lies in wait for the prince’s summons. But none of them carry the pizzazz of those in the first installment. Even Perlman’s growling one-liners, delivered in the course of the mayhem, seem second-hand, though he certainly still captures the gruffly humorous spirit of the character. Blair, Jones and Tambor go through their paces well enough but without the last measure of zest, while the trio who make up Krauss can’t turn him into a really interesting fellow (though the smoky effect of him in his gaseous state is cool), and John Hurt redeems himself somewhat for his dismal “Indiana Jones” turn in a flashback as Hellboy’s adoptive dad. The most serious flaw, though, has to do with the magical twins, who quite literally feel each other’s pain, and their royal daddy. These alabaster-hued figures (which actually turn into stone when killed) are simply dull, with Goss making an especially drab villain, looking a bit like an albino surfer-dude removed from his beach.

What we’re left to enjoy for the most part are the effects creations that seem to have sprung from del Toro’s own subconscious, influenced by his own loves and obsessions. There are the hulking monster Wink, who appears to be a cross between the Venusian creature of “Twenty Million Miles from Earth” and the cyclops from “The Seventh Voyage of Sinbad,” and the weirdly cartoonish “tooth-fairies” that attack the auction house, looking like Tim Burton creatures run amuck, and the horde of warriors that Nuada raises from the dust. And the leg-less scavenger who aids our heroes in the last reel, as well as the particularly del Toro-esque figure of the prophetess to whom he turns for assistance. And the huge “forest god” Hellboy must battle—a wispy, heaving figure that sends an explosion of fluff into the night sky as it expires. Even the site of the final showdown between Hellboy and Nuada—a place of giant wheels and spindles looking like the inside of a mammoth clockworks—is typical of the director’s vision, hearkening back as far as “Cronos.” Danny Elfman’s score adds a few appropriately Herrmannesque touches to complement the visuals.

But as fascinating as the images are to behold—and as well executed as they are by the director’s collaborators (production designer Stephen Scott, art director Elli Griff, costume designer Sammy Sheldon and an effects and makeup army headed by Michael J. Wassel and Mike Elizalde) and cinematographer Guillermo Navarro—they’re simply not enough to compensate for the movie’s comparative lack of zest and its more intimate longueurs (like a musical interlude for a drunken Hellboy and Abe, which is amusing at first but does run on). Perhaps it’s just the inevitable lack of discovery in a sequel that’s at fault, but though “Hellboy II” is clearly the work of a great visual craftsman, it lacks the energy, freshness and fun of the first movie.