Great, immediate motivation and hook. I love the horror elements. This isn't really a criticism, but I would like to see them fleshed out a bit more. How do the sludge and Father of Suns relate? How does the sludge meld metal to flesh? Or rather, why are people touching so many metal things after seeing what happens? Do they become magnetic? That could be a cool explanation. Or does the voice tell them to touch metal? it may be a good idea to just drop the sun theme altogether and make the guy the Father of Iron or something metal themed.
I really like the layout and a lot of the design. Great art. I can see what you're going for with the gradients, but I think all the different colors and the variety of methods for keying made it hard for me to identify when a color had meaning or not.
- I think the brighter room text means there's a story item there, right? Since you already list the item, I don't think you need that.
- Does the lighter shade of green used for the room text and one of the enemy colors in the key mean anything?
- I don't think you need the enemy tier system at all. You already have the associated symbol next to their names. You could remove the tier key at the bottom and even the lines extending from the enemy description boxes. I would even consider maybe giving all enemies the same symbol but in different colors. As it is, the symbols are hard for me to differentiate.
- Whatever symbols you do end up keeping and using, I would put every symbol in one box in a list. Having different symbols in different places makes it really hard to quickly get the information I would need as a warden.
All that said, there is a lot to like here! The design, layout, and art are great. The module itself is fun and well thought out. Overall, the biggest issue (in my opinion) is just that it's over-designed and could be pared back and streamlined to make it shine.