Every week this summer, we'll be taking an historical tour of the Hollywood blockbuster by examining an older film that is in some way a spiritual precursor to one of the weekend's wide releases. This week: if we're being classy about it, overt Twilight knock-off The Mortal Instruments: City of Bones could be more generously thought of as a new entry in that most modern of fantasy subgenres, in which mythological beasts interact with the glass and steel canyons of the big city. Happily, it is not hard for the bulk of such films to be better at it than The Mortal Instruments.

The word "fanboy" is almost invariably used A) disparagingly, B) in reference to audience members who rabidly consume stories in various genres of movies and comic books, and get profoundly angry at anybody who doesn't love their favored corner of the nerdosphere as much as they do. But this is not the only way to be a fanboy. In fact, a filmmaker can, himself, also be a fanboy (or "herself" a "fangirl", but I do not believe this has ever yet happened), and this, I find, is generally better than when a viewer is a fanboy; for a fanboy-director is likelier to be sincere and enthusiastic and respectful, while a fanboy-viewer is typically going to be a shouty, small-minded artistic totalitarian.

Of all the directors we could potentially call fanboys, surely the best one at it is Guillermo Del Toro - a man who in 2013 got to spend $200 million to make his giant robot toys fight his giant monster toys, under the name Pacific Rim, after all. But even that feature-length love letter to Godzilla is not, perhaps, the most overt work of fanservice in del Toro's career: for that honor, I would point to his 2004 adaptation of Mike Mignola's comic series Hellboy, a labor of love that the director (who also served as screenwriter) had been nursing along for years, passing up several surefire blockbusters to finally bring it to completion. It was not a flawless delivery of the director's precious baby - the script manages to be simultaneously overly-descriptive and helplessly opaque - but the one thing it would be quite impossible to claim is that the filmmaker's love of his subject isn't apparent throughout every lovingly-crafted frame. It is one of the most individualised and personally-stamped of all the films of the great superhero boom of the 2000s (which, increasingly, looks to be a different thing than the immediately continuous superhero boom of the 2010s), and if it doesn't end up feeling quite as much of a del Toro film as its sequel, Hellboy II: The Golden Army, it does feel much more like a Hellboy movie, and it is filled with a sense of gee-whiz joy that its follow-up, for all its flashier style and more baroque scenario, doesn't reach.

Which is not to say that Hellboy doesn't have flashy style or baroque plotting; in fact, those are perhaps the two things that most dominate. Plot-wise, the mash-up of several different Mignola stories plays very much like a Lovecraftian gloss on Men in Black, with an oddball investigatory agency based in New York squaring off against a tentacled cosmic evil, sprinkled with a healthy dollop of Nazi occultism, because after all, everything improves when you throw some Nazis at it.* It opens in the '40s with U.S. soldiers interrupting a plot by the immortal Russian mystic Rasputin (Karel Roden), clockwork cyborg Nazi assassin Kroenen (Ladislav Beran), and Aryan she-wolf Ilsa Haupstein (Bridget Hodson) to open a portal to a hell dimension filled with unspeakably evil beings, with only an infant demon making it through. 60 years later, that demon has grown - slowly - into a cynical but good-hearted lug named, with misplaced affection, Hellboy (Ron Perlman, ideally cast and wonderfully surly), who works as part of the government's Bureau of Paranormal Research and Defense, under the kindly eye of his adopted father, occult researcher Broom Bruttenholm (John Hurt).

That gets us out of the prologue and into the first act, and it's here that Hellboy gets a little messy in the writing. "Strained" might be a better word for. It's trying to cover a little bit too much territory in too compact a space, presenting an introduction to the characters (done through a bland origin-ish story involving new BPRD agent John Myers, played by Rupert Evans), while also playing as something like a procedural, showing what the team does in the course of their regular days, while also expanding on the Nazi villainy of the prologue, helpfully aided by three ageless Nazi villains. It frankly seems like it wants to be both itself and its own sequel, simultaneously, and this is not least of the reasons that the most straightforward The Golden Army is the better film. Though it's also what gives Hellboy it's personality, as there's a boyish sense of overreach that feels very different, and more satisfying, than mere shoddy screenwriting.

But it's really not the writing that drives the movie, and only slightly more its characters (who are, in the main, appealling and off-kilter without being annoyingly kooky). It's the design and the way that design is captured by del Toro's irreplaceable cinematographer Guillermo Navarro, who uses a hugely satisfying visual palette that's heavy on mood lighting and color balance that favors cool shades of blue, grey, and brown, all the better for the bright red Hellboy to pop right off the screen. It's a film that draws most of its power from combining a heightened but recognisable version of the real world (a depiction of New York that looks about as much like a comic book come to life with its graphic qualities intact as any city in any comics-derived film of the '00s) with stupendously elaborate and fanciful design, mostly of Hellboy himself, but also of fellow Bureau monster Abe Sapien (Doug Jones; David Hyde Pierce provided the voice, but refused onscreen credit when he watched the film and realised how fully Jones's acting did all the work of creating the character), and the otherworldly Kroenen, in both his implacable mask-wearing and hideous animate corpse editions.

In fact, Hellboy is so effective at marrying its fantasy action with stylised urban settings that in the final chunk of the movie, taking place in the only overtly fantastic locations of the whole film, it looses quite a bit of energy; it definitely doesn't help that the broad, comic-book style action choreography increasingly degrades into something very typical and CGI-addled: Hellboy was not a very costly film, and its digital effects have not aged well, making it gratifying that del Toro made certain to create so much of the effects through practical means (something he has generally done throughout his career, culminating in the bestiary of his very next feature, Pan's Labyrinth). So much of Hellboy is a breezy, imaginative treat, that it's a genuine disappointment when it turns into just another damn comic book movie.

Still, even at its worst, the film is suffused with a spirit of wide-eyed amazement at its own fantasies, with plenty of spooky-fun creatures that work as black comedy and as campfire story in equal measure. And Perlman's Hellboy is one of the truly great comic hero performances of all time, with the actor managing to be shockingly expressive under a deadening amount of latex. It's nowhere near del Toro's finest achievement, either as a story or as a work of visual imagination, but there's at least a possibility that it's his most untroubled and fun work, meant only to delight and awe, and largely successful in both aims.

(NB: There is a director's cut, more than ten minutes longer than the theatrical, and though I am sometimes agnostic on these issues, there's no contest: it's an improvement across-the-board, clarifying plot details and making the sketchy characters quite a bit more real and lived-in).