- Alternative Character Interpretation: With the ending of Elysia where the Cthulhu Cycle gods are rendered amnesiac and trapped by the Elder Gods at the beginning of time, some wonder if they're actually the Elder Gods themselves.
- The main characters' tendency to attribute their occasional acts of stupidity to the insidious mental influence of the CCD over their thought process: legitimate justification due to telepathic attacks by the CCD, or smug Never My Fault self-justification by overly-cocky protagonists who can't admit they blew it?
- Broken Base: The entire series is both loved and loathed by fans of the Cthulhu mythos. This is due to the fact the Cthulhu Mythos deities are shown to be Always Chaotic Evil rather than Blue and Orange Morality, have the protagonists able to regularly Did You Just Punch Out Cthulhu?, and also introduce a bunch of Good Counterpart Elder Gods. For those who prefer the Mythos as Cosmic Horror Story tales, this can be disconcerting. Others, however, enjoy them as fun Pulpy adventure tales.
- Complete Monster: Ithaqua, the White Silence, the Wind-Walker, is a powerful Great Old One, and one of the most malicious of his kind. Ithaqua lurks in the snows and the wind, devouring those he comes across. Others are taken to his world of Boreas to serve him eternally, where Ithaqua demands loyalty and blood sacrifices. Many women fare worse, as Ithaqua is a Serial Rapist in his quest to create a half-human child to help him unlock the prisons of the Old Ones to destroy all that lives. On Boreas, Ithaqua is a brutal tyrant, regularly massacring his enemies and torturing captives with sadistic relish, including his own followers. When he believed he had bred a perfect eventual mate to bear a child, Ithaqua callously murdered her entire village and clan with no further need of them. Despite his alien nature, Ithaqua's lust and need for dominance are all too understandable for those who oppose the evil of the Great Old Ones.
- Ho Yay: Titus Crow and Henri have a much deeper relationship with each other than they do with their respective love interests.
- Negated Moment of Awesome: In one of the Titus Crow books, the characters visit a nightmare factory in the Dreamlands run by the Great Old Ones where the collective fears of humanity are collected and then physically manifested. The reader expects some truly horrific imagery, instead we are treated to the heroes being threatened with some distorted versions of werewolves and vampires. Apparently a Monster Mash of stock vampires and werewolves was the most horrible thing mankind's collective unconscious could produce. Could be Fridge Brilliance, if it's a coy hint that most humans' imaginations are prosaic enough that generic Hammer Horror fare is as creative as their nightmares get.
- Values Resonance: Brian Lumley goes out of his way to invert Lovecraft's themes. Intermixing with ancient gods and monsters is a GOOD thing. Albeit, this clashes with the Early Installment Weirdness of the Chthonians being Always Chaotic Evil from birth.
YMMV / Titus Crow