Hey ! Thank you for your comment ! Sorry for my very late answer.
I'm Théophile Catella, that is to say Snowy Path's Lead game designer. I'll try my best to answer your questions.
About the snow effect :
This is one of the most challenging task we have to face. In this POC, we simply used particles produced by the Unity particle system. Particles emmited are white squares, facing the camera (billboarding emission) and spawned above the player. It works with a low poly art direction, but it is absolutely unusable with other art styles.
The current Snowy Path production is a stylisized art based game. Plus, we had some optimization issus with that system. Consequently, we switched to VFX. It is honestly way better, namely for the blizzard effect.
About trees movements :
I'm a game designer. To be totally honest, I just don't know how my team made it work but they did ^^.
Actually, Jerôme Dambraine worked on the trees. I'll tell him you left a comment.
About ZQSD binding :
I totally understand why you found it weird : because it certainly is if you're using an international QWERTY keyboards. In France, we traditionnaly use AZERTY keyboards. As a consequence, our game movements are mostly binded on ZQSD. As a matter of fact, this POC is mostly destinated to promote ourselves in order to facilitate our job research, which mainly takes place in France. If a recruitment consultant plays this POC, he'll consequently certainly play it on a AZERTY keyboard.
I'm really pleased you played Snowy Path, and I hope you enjoyed it. Thank you for your time, that's really cool seeing our game can interest people!
Have a nice day.