Hello! I ran this last night in the basement of our games shop and wrote up an AAR and some playtest notes. TLDR: interesting approach and I love the restrained focus of what you're going for, but needs a bit of work to make full sense of kind of experience it should be, and why a DM wouldn't just use OD&D. I hope there's some useful feedback in the article:
https://ludicghoul.blogspot.com/2025/10/the-gresseham-miasma-hammers-rpg-aar.htm...