I'll say this for I, Frankenstein: It delivers what it promises. This is DEFINITELY a movie about Frankenstein's monster (now known as Adam) battling demons alongside tepid gargoyle allies. It even does that job reasonably well, with fluid fight choreography, artsy camera work, and a motif brimming with gothic...everything, basically. It also makes the commendably bold choice of basing its anti-hero and plot specifically on Mary Shelly's original novel, rather than the more recognized and therefor marketable Universal Studios incarnation. Unfortunately, by simple virtue (or is it sin?) of being a movie, it also makes IMPLIED promises of such things as plot, dialogue, characterization, and most-notably, PACING; that iconic bell-curve of story progression we learned in elementary school. (Setup, Conflict, Climax, Conclusion; if I remember correctly.)
Such subtleties are scarce here, and you miss them immediately. Before the opening narration is even all the way done, Adam is attacked by demons and rescued by gargoyles [NOTE: They're also angels, basically; I forgot to mention that in the original review]; both out of the blue. They offer him (not to mention us) the brief pleasure of a supporting cast, and then he leaves, narrates some more, fights some more demons, flashes forward, narrates some more, fights some more demons, revisits the angels, who do some demon fighting on their own, and once in a while there's a conversation, to remind you this isn't a video game...is the snark I would've made two decades ago (and other reviewers have already expressed such an opinion), but these days there are plenty of video games that have more dialogue than this film and are less linear to boot.
Once again, the problem isn’t even that anything that’s actually in this movie is necessarily bad. It looks nice (read; it’s ugly as sin, but that’s appropriate in this case, and it’s detailed), almost all performances are competent (if none even remotely impressive), and as mentioned, the action scenes work fine of themselves. The problem is that a lot of good things aren’t actually in this movie. Without the elements that anchor the trailer-filling fight scenes together, it’s a disorganized mess that makes you wonder why you aren’t watching another action/horror movie; you never get a good feel for exactly what part the barely-existent story you’re seeing. In fact, it’s arguable that the climax of this film feels less climatic than other scenes. (I won’t spoil it, but there wouldn’t be much love lost if I did.)
All of the above content would be sufficiently damning on its own, but I have a few more nitpicks to impart. The first is that, due to the film’s constant kinetic pace, any ability to take seriously its backstory of a secret Heaven-Hell war raging under our noses for centuries, quickly flies out the window with a rain of shattered stain glass. Somehow, despite both being able to transform into human form, neither the demons nor the gargoyles care a whiff for subtlety when they get down to their jobs, smashing things and vaulting through the sky in full-view throughout a European city (the film never specifies which one) that is somehow still intact and populous in spite. All that might be a bit more forgivable had the film been even remotely self-aware and whimsical, but its humor is limited to a few dry situational snarks.
Which brings us to the second additional nitpick: Tragically, despite its unique concept, and despite applying a technically appropriate style to that concept, an action film has never felt so cliché. The ugly characters, dark alleys, and halls are perfect for a franchise gothic from the start, and the Latin choir score and existential ramblings gel perfectly with the biblical theme. Had it come out in some other time (and, it should go without saying, evaded at least some of the flaws I stated above), I, Frankenstein could have worn such distinctions well. In the present era, though, thanks to the success of such films as The Matrix and Batman Begins, we’ve spent a decade full of action films abusing such morose tropes. Onward through the 2010s, just when you think Marvel’s films have won their final heroic battle against that conformity, another black sheep comes along to add to the sludge of a long mostly-black flock.
All that being said, I can say one thing emphatically positive about this movie: It’s a blast to make fun of; like no other B movie in recent memory. I’ve had some great laughs today, all the way from hearing my friends weigh in their thoughts, through reading critics’ reviews of this movie, to writing my own. Describe it at any length, and jokes write themselves that I didn’t even know I had before I started it. This dubious honor may well grant the film a twisted sort of immortality—much like a lightning bolt frying a corpse.