Spire Climbers drops Iro and Emil into a situation that’s considerably more dangerous than anything they faced as trainees. They’ve opened their first Gates, unlocked new talents, and earned promotions, but their reward is a squad of strangers with their own agendas and a mission to push deeper into the titan than anyone has gone before. The massive alien starships that humanity depends on for survival remain as mysterious and hostile as ever, and the spires that rip through the titan’s hull represent both the greatest threat and the most promising source of new resources the fleet has encountered.
Rob J. Hayes published the first Titan Hoppers book to positive but measured reception. With Spire Climbers, the consensus shifted noticeably. Readers who found the first book promising but uneven came away from the sequel impressed by the improvements in pacing, character work, and worldbuilding. The progression sci-fantasy genre has grown crowded, but Hayes carved out a distinctive space by setting his story aboard crumbling spaceships rather than in dungeons or towers, and this second entry capitalizes on that uniqueness.
The Titans and the Thrill of the Unknown
Worldbuilding in Spire Climbers takes what was merely intriguing in the first book and expands it into something deeply fascinating. The titans are massive alien vessels, and humanity doesn’t understand them. They don’t understand why they exist, what created them, or what lies deeper in their interiors. Hayes reveals new layers of this mystery at a pace that rewards curiosity without resolving things too quickly. Each expedition into the titan’s depths uncovers something strange. Pitch black oceans where nothing should exist. Nests of creatures that seem designed to guard specific areas. Spires that pierce through the hull with no clear origin or purpose. The sense of exploring something vast and incomprehensible gives every expedition a tension that goes beyond the immediate physical danger.
Hayes’s progression system gains depth alongside the worldbuilding. Iro and Emil’s Gates, the mechanism through which humans acquire supernatural abilities, feel more fleshed out here. The talents they unlock interact with each other in ways that create genuine tactical considerations during combat, and Hayes does a good job of making each new ability feel earned through the dangers that unlocked it. The growth never feels handed to the characters. It comes at a cost, and that cost is visible in the damage they take and the close calls they survive.
Squad dynamics carry the emotional weight of the book. The new team is a collection of clashing personalities: an explosive mage, a cursed surveyor, and a vanguard whose loyalties aren’t entirely clear. Watching these characters move from mutual suspicion toward reluctant cooperation, and eventually something closer to trust, follows a familiar arc but Hayes executes it with enough specificity to keep it engaging. The friction feels genuine rather than manufactured, and the moments of unexpected solidarity land with real warmth.
When the Action Never Stops
Action fatigue is the criticism that surfaces most consistently. Hayes writes combat with cinematic intensity, making every fight feel kinetic and consequential, but the sheer volume of action sequences can become overwhelming. Some readers found themselves wanting the book to slow down, to spend more time in the quiet spaces between encounters where atmosphere and mystery could breathe. The pacing is breakneck by design, and for many readers that’s the appeal, but those who prefer their progression fantasy leavened with more reflection will feel the relentlessness.
Secondary characters outside the immediate squad receive limited development. The broader fleet and its political structures exist mostly as context rather than as lived-in spaces, and characters who appear between expeditions don’t always register as fully realized people. This isn’t unusual for progression fantasy, where the focus naturally gravitates toward the power system and the immediate challenges, but it does mean the world beyond the titan’s interior feels thinner than the world within.
Being a middle entry also works against it slightly. While it improves on the first book in virtually every respect, it doesn’t resolve the larger mysteries it raises. Readers who need complete arcs within individual volumes will find the ending satisfying on a character level but frustrating on a plot level.
Deeper into the Dark
The central question Spire Climbers asks, what lies at the heart of these alien vessels that humanity depends on for survival, is compelling enough to carry the series forward with genuine momentum. Hayes has built a setting where every answered question generates two more, and the progressive deepening of both the characters’ abilities and the mysteries they’re uncovering creates a feedback loop that keeps pages turning.
Should You Read Spire Climbers?
If you’ve read Titan Hoppers and wanted more, this delivers in every category that matters. It’s also a strong choice for readers who enjoy progression fantasy but are tired of the standard dungeon or cultivation settings, as the sci-fantasy framework gives familiar progression beats a fresh context. The squad dynamic will appeal to readers who like their adventure stories focused on team chemistry under pressure.
Skip it if you haven’t read the first book, as this picks up directly from where Titan Hoppers left off. Skip it if nonstop action wears you down rather than energizes you. And skip it if you need your progression fantasy to come with substantial worldbuilding outside the immediate adventure, because the fleet and its politics stay largely in the background here.
The Verdict on Spire Climbers
Rob J. Hayes takes the promising foundation of Titan Hoppers and builds something thrilling in this sequel, with expanded worldbuilding, tighter squad dynamics, and action sequences that read like cinematic set pieces. The relentless pace occasionally tips into exhaustion, and some secondary characters don’t develop beyond their initial function. But the core mystery of the titans themselves and the visceral satisfaction of watching Iro and Emil grow through increasingly dangerous missions make this one of the stronger entries in the progression sci-fantasy space. It’s the rare sequel that makes the first book better in retrospect.