I own most of printed Apocalypse Engine books and this is the one I like the least.
The theme of the book is a Ragnarok of sorts where dwarves rise piloting giant metal monsters. Not bad. Mankind responds rising the bones of giants (and the wrath of the living giants!) to fight back. Cool. Even elves are said to start using treant like suits of armors. Fine.
But then the writer lost focus and and kept on investing much of the little page count talking about clans and foreigners... in case you wanted to play with a roman-ish or celtic-ish character. The evolution and development of starter stories to the central premise is a long shot.
We got used to quality with games PbtA: Urban Shadows, Dungeon World, Monster of the Week, Tremulus, Spirit of 77, Legacy, City of Judas, etc. This book is clearly a sign that people started churning out books just to join the fad, without much foresight or care.
For the price they ask we deserve much more.