Cool concept but I it is really hard to tell how far the dog with make the sheep go and in what direction. Also, a fullscreen window would have been nice. Even with the criticisms it was fun. Good job!
Your comment is very clever: I don't develop any "tips" for the position where the sheep will go because I thought that thing could made the movement less "out of control". Do you have any idea for it? You are right for the fullscreen windows, I totally forgot it! :D