Since Pixeljoint has a built-in zoom function, you should never submit "pre-zoomed" artwork, I suggest re-uploading it with it's original size.

Translucency effects like the snow aren't usually allowed on PJ, since they create colours outside of the artist's direct control, and PJ has a strict-ish definition of pixel art.
In addition to the snow, there are some odd colour distortions on the sprites, perhaps as a result of trying to convert each frame from hundreds of colours (because of the snow) to ~256.

A "clean" version without these issues is more likely to be accepted.