Neat idea! Very hard to keep them all in. I lost most very quickly and only managed 1:15 before the last sheep ran off! The game controls well though I wonder how it would play if you could see the whole map at once.
When I started in my head you could actually see all the map at once. But then, When I made the sprite something with the proportion was off, Happy was too small. To fix that I zoomed in and unlock the camera. That's it XD