It's an interesting idea, but at this moment it is not fun to play. The ground detection doesn't work very good. That combined with how the scaling locks to one direction makes it really annoying to use.
That beings said, when you get the feeling of it and you have to run in a straight line, it is pretty satisfying. I would try to make the scaling not limited to cardinal directions. Use something different for the player, because a snake is a pretty one dimensional animal, so you can't play to much with it's scale. Also I think it could be beneficial to even give up the extra dimension to make it 2D, so that the player can control the scaling more precisely.