Great idea with this -- it's rare that games focus on dismantling a single powerful entity, even when they're otherwise focused on combat. As your long list of inspirations points out, it's definitely an established trope... so why not explore it in TTRPGs?
Favourite details: The hot and cold tokens are a really cool (ha) way to lay the groundwork for the climax. I particularly like that it means everything before the final fight matters, even if it's not moving in the "right" direction. And just speaking generally, I think the writing is really clear here! It's nice to see strong technical writing in an indie game, because sometimes that element falls to the wayside.
Would be nice to have: A link to your page or credits on the PDF! Credit where it's due, right? :)