Despite the somewhat negative reviews, I do congratulate you. Many games don't even get to see the point were they are reviewed.

Its funny though how different the three reviews are. While the first says "Farmer Joe's is quite a simple easy to get going on puzzle matching game. Easily comprehended by all ages" the third writes: "When I first played this I thought it was one of the most frustratingly difficult games I had played in recent memory".
I'm not entirely sure what to make of that.

Of all reviews, I found the second to be the most helpful. As a reader I'm not really interested if the reviewer found the game boring or too simple. I'll decide that for myself. No, what's more interesting in the 2nd review is that he's mentioning things like bad sound and glitches in gameplay, text that doesn't fit properly. Things you, the developer, can do something about.
More even, he writes, "They (the levels) weren't just too easy, there didn't appear to be any way to lose at all!"
That's something that didn't even come to mind when I played your demo, but perhaps is a good point to think about for a next update. Unless you wanted it to be that way of course.

All in all, I'd say a -6 isn't great, but not bad either. Especially considering nearly half of all other games reviewed there, were rated a 5 or even less.

Looking forward to your first sale!