The main distinction of eggs comes from how they look: melting popsicles, metallic bodies with a frosty crystal glow. Glowing adds an extra level of dimension to your game, as well. Besides the look, it also impacts gameplay۔
Moreover, it makes some items shoot more easily than others and allows for storage in a refrigerator (though you can still cook them on the stove top). It has no effect on anything else; just buy one or both if you prefer how they look above all else!