This is thematically delicious, the setting is so wonderfully conveyed with minimal space.
The hacks here for (dis)advantage, crits, hp to cast, magic item activation, the expansion of enemy HP as DS to generalized obstacles, the character classes - this is really, really fucking good and, moreover, conveyed tightly and cleanly.
The only thing really missing that I'd love to see is a character sheet with quickref! This is great!