It's an honor to have been the subject of such an in depth, and thoughtful review! You managed to pick out a lot of intentional detail that I thought might have been lost due to the short nature of the game.
You're right that the trees stand out of when compared to the rest of the scenery - that unsurprisingly wasn't totally intentional. It was the result of me trying to build a shader that puts snow "on top" of stuff, if that makes sense. In short, it checks upwards facing normals and adds a noisy white texture to those faces depending on exactly how "up" they're facing, to simulate snow laying on those surfaces. It had the unintended effect of giving the trees a lot of depth and texture, and less like they were covered in snow - but I liked it, so I left it in.
Regarding the music I made - all of the game assets (including the music and sfx) are in the repo (https://github.com/hey-tack/a-short-walk-in-the-snow). I left the repo unlicensed, so technically I haven't given express permission to rip audio from the game - but because it's public, I couldn't necessarily stop you, if you catch my drift.
If it's easier, I went ahead and uploaded the music on SoundCloud (https://soundcloud.com/hey-tack/a-short-walk-in-the-snow). You can download it from there if you like. The music felt very empty without the windy ambiance, so I composited that into the track. If you're interested in a totally raw version of the music (which is in the repo), let me know and I can upload that too.
Thanks again for the glowing review - It really makes me happy to hear it resonated with you!