What can I say? The book was amazing.
The plot had a wonderful set of twists, and the implementation of it was spicy.
Jacob Lyre, the main character, is your average Joe and he plays that role well. He makes mistakes and has to deal with the consequences of overconfidence, rash thinking, and taking an optimistic rather than pessimistic, or realistic perspective.
I think the world-building of this story is better than other stories—it's not too little nor too much. In certain chapters, more details could be needed for certain situations, but how the author decides to do so is up to him. Perhaps in certain situations, fewer details are better than usual. (Although, something such as describing the misty atmosphere or the rusted piping, showing how Jacob is heading into a more industrial area. It is the little details that help readers appreciate the story more.)
The pacing is a bit too hectic for my liking, but so be it. Some stories work better if they move faster. (At least you aren't pulling a Psychic Parasite and having the main character finally start taking action by the 30th chapter, whereas the past 30 were delineating everyone's lives BUT the main characters and eventually killing them off/making them useless at the end.)
And to cap it all off, we have a snarky and cocky "system" which "reflects Jacob's personality", providing comic relief in dire situations. Honestly, I love this twist. Jacob's thinking and behavior are shown through the system, along with his personality, and the possibility of future character development is allowed, both for Jacob and the system. Despite that, BB (the system) shines brighter than the main character at some points, such as providing critical information, with the limitation that he can't do much during combat (due to restrictions imposed by synchro mode). Although the system tends to lead Jacob by the leash with the rewards for emergency quests, there are no dire failure rewards, such as the cliché "Failure: You die." moments.
The plot armor consists of "Emergency Quests", unique rewards, and random encounters, while Jacob is being ignorant (but we don't talk about that. That's bound to happen within any story, so deal with it, you critics.)
It's a great story all in all. From the plot, setting, characters, and abilities, to the snarky system and events that occur within the story. Well worth reading! I'm still at the beginning of chapter 33, so I'll be updating this if there's any noteworthy changes.