I love the cover and the core idea behind the unfathomable vaults! Many of the table results are highly imaginative and lend toward having the players explore their characters. I wonder how easy it may be to implement some of the results. For example, I love the Living Gem; that's a fun and hilarious way to present a practically impactful choice. The Rusty Crown below it is likewise an intriguing idea, though I'm less clear about how to pull that off. Nonetheless, it's full of entertaining ideas, and you've given nice, structured rules for exploring this nebulous locale! Good job!