- Anticlimax Boss: Dekar is built up to be the muscle among the demons who could even take on Adam, only for him to be quickly carried away and killed by the gragoyles when the two finally meet.
- Critical Dissonance: Professional critics savaged the film, but while casual audiences didn't exactly consider it good either, they acknowledged the movie was an entertaining and rather imaginative (if clich-based) effort.
- Designated Hero: The Gargoyle Order is nominally a force for good, making sure humanity isn't enslaved by demons, but they hardly act like it. Gideon treats Adam as an abomination to be destroyed (understandable, but still dickish since others are more accepting), the Gargoyle Queen can't seem to keep a consistent opinion of him, and the only two members who consistently treat him like a person die in the first major battle just to make sure the rest of the order hates him. When a single human is killed by a demon that Adam was fighting, they blame Adam even though the demons are the ones hunting him and (as far as we know) this is the only time in 200 years he's screwed up as such. When the demons raid the cathedral to get him back and kill numerous gargoyles, they again blame him even though they locked him up there to begin with. Finally, he comes to them, outlines the Big Bad's plan, and wants the safety of himself and a human he's protecting in exchange for the location of the Big Bad's lair. They then proceed to try to kill Adam, ignoring the safety of said human (note the above dead human complaint) and the fact that killing Adam at this point in no way impacts the Big Bad's plan. Adam basically has to trick them into actually stopping the Big Bad, and it's only because he picks up a soul along the way that they finally treat him with respect.
- Fridge Brilliance: Many reviewers have complained that Aaron Eckhart's performance seemed flat and emotionless. There are two reasons this could count as Fridge Brilliance. One, it could be done deliberately to emphasize Adam's soullessness. Two, Adam has just spent two hundred years living in the wild, his only contact with the outside world the demons who try to capture him. Being in isolation for even as little as a few months can cause people to start just shutting down emotionally.
- Fridge Logic: If any weapon engraved with the religious sigil can descend a demon, what about tattooing the sigil on yourself?
- Ham and Cheese: Bill Nighy, of course.
- I Am Not Shazam: Played With. "Adam" is the name the gargoyles gave him (based on how the monster called himself once in the original novel) while "Frankenstein" is the name the demons call him, justifying it as him being his creator's legacy. He chooses good in the end, but accepts the demon's reasoning behind his name.
- Informed Deformity: Adam is just Aaron Eckhart with some nasty facial scars. They're definitely noticeable, but they don't really detract from his rugged good looks, and certainly don't look inhuman. The idea that he's outcast from humanity because of his hideousness isn't really plausible.
- Narm Charm: A movie about angelic gargoyles fighting demons with Frankenstein's monster in midst only could be entertaining, hysterical or both.
- Special Effects Failure: While not truly wretched, there are times in which the gargoyles really look like cartoons.
- And the demons sometimes just look as if they're wearing demon masks from Halloween Adventure.
- They Wasted a Perfectly Good Plot: Admit it, you were hoping the whole movie that Adam would carve the triple cross on some bullets.
- What an Idiot!:
- The Gargoyle Order: refused to make fake copies of Frankenstein's notebook, rip out the important pages or, you know, just destroy the book altogether. Later on, as demons assaulted the cathedral, the gargoyle, who are obviously defending, start chasing the demons and leave their home defenseless.
- Dr. Wade (and her co-worker): refused to scan and preserve a centuries-old notebook and work on the digitized version. Instead they insist on flapping the pages around like schoolkids.
- After Wessex's true identity is revealed, instead of just telling her co-worker to escape, Terra agrees to meet him alone. Bonus point for Adam, who lets her go while the audience groans.
YMMV / I, Frankenstein