Hellboy II: The Golden Army, 12A

A strange thing about comic-book films: the higher the stakes, the more lightweight the result. In The Dark Knight, it's only about the Joker stealing piles of money and being a pain in Gotham's municipal arse, resulting in a lumbering cogitation on good and evil – Dostoevsky in a rubber jumpsuit, no less. By contrast, in the last Fantastic Four film, Rise of the Silver Surfer, the Earth is about to be devoured by an interplanetary scavenger, while in Hellboy II: The Golden Army, humanity is menaced by an avenging legion from the dawn of time, and in both cases – well, I think the appropriate word is "romp".

Personally, I'll take the romp option every time, especially if a director such as Guillermo del Toro is at the helm: the Mexican prodigy has an instinctive understanding of the craziness, telegraphic frenzy and dense visual clutter that often characterise the great American comics.

And he relishes the childlike pleasure that can give these comics their special edge. I'm not being condescending if I use the word "childlike". The Dark Knight bends over backwards to insist that it's terribly serious and adult: it smacks of the earnestness with which some people insist on using the term "graphic novel". Del Toro, on the other hand, is strictly a "comics" guy. He knows that what we love in superhero comics is often the simple stuff: good-zaps-evil storylines, big baroque monsters, jazzed-up colour, a dash of fairy tale.

Based on Mike Mignola's comic series, the Hellboy movies are also childlike in the sense that their characters essentially are children. That point is made in the opening sequence, where we meet the film's hero as a boy, a weird-eyed, buck-toothed, enthusiastic all-American kid – except for his horns, red skin and huge stone fist – being told a bedtime story by his adoptive dad (John Hurt).

Years later, the adult Hellboy (Ron Perlman) is a hulking, cigar-chewing galoot working for the Bureau for Paranormal Research and Defence, an agency battling alien menaces. The BPRD resembles a school for gifted misfits: chief agent Tom Manning (an inimitably flustered Jeffrey Tambor) is its headteacher, fish-like alien Abe Sapien (rubber-limbed Doug Jones) the resident swot, and Hellboy's girlfriend, Liz (Selma Blair), the punkish, pyrokinetic head girl. And when a new agent, Johann Krauss, arrives from Germany – a wisp of ectoplasmic smoke in an antique diving suit – he's fundamentally a pushy prefect.

As a school story The Golden Army makes lighter work of the whole business of growing pains than the Harry Potter series. A bewildered Hellboy lunkishly moons around after his spats with Liz, and what makes it touching is the dazed gaucheness of his double-takes: what you can see of Perlman through the crimson make-up suggests a gentle bullish innocence.

The story, by Del Toro and Mignola, feels almost like an afterthought. A high-kicking, sword-wielding elf warrior (Luke Goss, not half as creepy as when he was in the pop duo Bros) is after the crown that will enable him to overthrow humanity. But that's just the hook for a series of extraordinary action sequences, executed with Del Toro's usual depth of design imagination, and punctuated with goofy, sweet-natured comedy routines: Hellboy gets beaten up by a wall of lockers, Hellboy and Abe get drunkenly maudlin to a Barry Manilow song.

As for the spectacle, you won't feel short-changed. First, Hellboy's team face a battalion of nasty little creatures called Tooth Fairies, so called because they eat teeth: a sequence in which CGI completely justifies its existence in its ability to conjure up swirling, swarming multiplicity. Even better is the battle with a giant tulip-headed forest god, whose spurts of green blood burgeon into explosions of lush vegetation. As for the Golden Army itself, these clanking automata are realised with a 3D intricacy that suggests The Transformers, but on an artisanal, almost Fabergé level.

Lovers of old -fashioned latex will also get a kick from Del Toro's character designs, which have the same nightmarish quality as his Pan's Labyrinth: among them, an antiquarian with a cathedral for a head, and an Angel of Death with wings full of eyes, authentically smacking of Gustave Doré eeriness.

The film's substance, undeniably, is in the design and the staging. The dialogue is thin and some of the humour wheezes: the jokes about Krauss's heel-clicking Teutonic fussiness ("Over und out!") are as clunky as his diving suit. But the film's exuberance, and the sense that it's all one big gimmick-packed action toy, give Hellboy II: The Golden Army a refreshing cinematic purity: what you see is what you get, without any spuriously sombre subtexts wheeled in to reassure adults that it's OK to be watching this.

Right now, Del Toro makes this sort of film better than anyone. Indifferent as I am to Tolkien, The Golden Army even makes me eager to see his forthcoming version of The Hobbit. It should be really something – if he can keep Barry Manilow out of it.

'Hellboy II: The Golden Army' is on general release from Wednesday