This could use some numbers (how often do my workers fire the circle? how long will it take?) and some convenience features (if I hit the tier 2 buildy thing but don't have the materials, please queue up the tier 1 buildy thing).
That plus a little automation (auto sell? specify ideal number of workers and it'll hire them?) and it'd be _chef's kiss_ good.
Very much enjoyed this, thank you for making it.
Definitely enjoyed the circle progress bars. That's new to me.