Great simple game, but a couple of flaws:

1. Can't see stats. When the +5 and X2 processing amount upgrades didn't stack like I thought they would, it drove me crazy. I had to flick the cursor over processing as fast as possible to figure out how much I was shearing per tick, because I expected 7 and ended up with 12. Then I enjoyed the rest of the game, but that's most of the reason I didn't give it 5 stars - the stats were invisible.
2. No way to see the size of your shears. This causes less of a gameplay issue because the strategy remains the same regardless, but it still bugged me.
3. Generally speaking, the invisible stats. I'm guessing it was a design choice, considering how universal it is, but it bothered me the whole way through. How many sheep did I have? Hell if I know. I took a +10 at some point, and then stuck to X2, so... maybe 102?