Outstanding. Just really, really well done.
Broken down by criteria, spoilers for those that haven't finished it:
Implementation of Theme:
Yeah, I mean, nailed it, obviously. Two people keeping each other alive in the most hopeless situation imaginable. One of them is a wolf. Yep, all checks out.
Story:
Excellent job of making both Judah and Birch feel like real people instead of characters. One of the biggest questions I had in the early stages of the story was how these two got to this point in the first place, and when those reveals happened they not only made sense from a plot perspective, but really contributed to fleshing out each of the characters. Seriously, almost every detail provided here goes such a long way to developing the characters, their relationship, and the world around them.
I think the romance was handled fantastically as well. Developing that side of their relationship right at the end felt even more impactful and tragic than if they'd been romantically involved the whole time. Managing to turn the end of this story into something that still somehow felt positive was really impressive.
Presentation:
Also great. The choices in color palette really worked, with the purple conveying the post-apocalyptic setting in an interesting way that complements the more drab grays and browns. Minimalist art style for the characters really worked for me as well - expressive enough to convey what you needed but let the characters speak for themselves rather than relying on super attractive sprites. It almost felt like reading someone's journal from the event at times.
Final sequence, as alluded to previously, was beautiful and powerful despite the body horror.
Creativity:
One of the most impressive things, in addition to the above, is how well the lore was done for this story, especially in such a short narrative. The nature of the plant scourge felt fully fleshed out and that helped color the characters' existence in that universe. Obviously romances focusing on carpe diem/memento mori aren't necessarily new per se, but the execution here is off the charts and that's the most important thing for me.
This was just really good and something to be truly proud of. I'm glad I got the chance to read this.