Thank you for your answer. You've just proven some points that I have already made out for myself.

The snow looks great, but the tree and feather textures are very noisy and could use some polish. In particular, I think using your darkest colour right next to the highlights doesn't work very well here, and there are a lot of very irregularly-shaped clusters and isolated pixels that don't help the textures read like anything in particular.

Don't worry so much about showing every single detail, instead focus on creating a sense of the directional flow of the textures and the larger forms that they're a part of. With pixel art, there isn't room for every single detail, so you need to focus on the important stuff. Even when working in high res, artists often sacrifice details and textures to make what remains read more clearly.