MrFrettz I am assuming based on the animation that cody is supposed to be throwing directly to the right, and there is no aiming up down?
if so what I said stands, think final fight, which your game is...with snowballs...
if a character gets a certain height above or below you, your attacks start missing..basically if your feet are within a certain Y height of the enemy you are face to face with them, to high and too low they are to your left and your right respectively...
regarding the snow sprites, a tiled background would be much better and give better performance,also will remove the lines, only trouble is you cannot animate them...
what I would suggest is a tiled background for the snow, and if snow is used in a certain area add a sprite that can then turn into snowless patch on top of the tile, as there will be less patches than snow it will reduce your object count considerably...