Sorry it took longer than I thought to give it a try.
My first critique is the control scheme needs work.
Moving the sheep left and right works fine as there is plenty of screen to the sides of the sheep, but moving up and down is problematic, especially with that ad on the bottom.
Maybe make it tape & move style. Think Diablo/Diablo2. Where the user taps on the screen and the sheep moves to that point, instead of tap and hold to get it to move.
I’ll try it some more later, but the movement problem’s frustrated me, and if I were to have just come across it on the app store, I would be inclined to uninstall it and move on to something else.
The concept is fun, and the graphics are nice. I like the fact that the maze randomly generates, and that the sheep glows blue when I run over a crystal, sometimes I didn’t even notice the crystal until I ran over it.