Love this one! Reminds me of The Buried Giant by Kazuo Ishiguro. I think the way you've made this system agnostic is also very clever, though it took a moment for it to land with me. Seems like you could pick this up and run it in any system, taking only the read time plus another five-ish minutes to prep.
I will definitely be stealing the woods, with the rivals and pit traps, for another game sometime! The kid in the cogs is also a great encounter.