‘Gunmetal Gods’ is an awesome book title, and a promise to the reader to deliver those gods. The book unreservedly succeeds in this; the gods are immense, and deliciously baleful and lovecraftian. But they take a while to appear meaningfully in the narrative, in name or affect, and this results in the first half of the book failing to spark a lot of interest from me. This is largely because our human narrative (set against crusades style conquest of a holy city) lacked motivations or objectives I could invest in, and also simply did not live up to the expectation set by the time. This is entirely resolved as the story progresses and the animosity between our POV characters is solidly founded and proper investment is given to our main protagonist.
The prose is generally solid (actively good when it concerns the titular gods) but can occasionally fail to satisfyingly deliver what is happening on the page, generally in the grander action scenes. The pacing progresses quickly and occasionally to its detriment with some scenes feeling perfunctory or underserved.
The characters are complex, believably-motivated, with strong emotional foundations, and compelling. (Micah is particularly good in these regards.) And these motivations, as well as the character’s actions and personalities, are effectively infused into the narrative and allowed the affect it, building to a conclusion that is personal, tense, and satisfying.