Jeremy: your population will fill all of the available jobs heading downward. If nobody is working on tools, it is because you have too many farm or wood jobs. Overbuilding can slow you down until you've enabled the ability to control your workers.
Liked it. Smooth controls, simple but clever concept. I can see potential. On the other hand, it doesn't have much replay value for me.... needs achievements and stuff! And more variation in the circles movement or something too.