I liked it!
I think you can adjust at least two things:
1° The cost of dodu and barbu
The "problem" occurs when you're trying to go further. The cost is about to double, but it's make illogical when you look the capacity. For example, a barbu can cost 2K, then 4 ... When you reach a point, it's about hours of farming without increase.
My example?
I've 15 dodus for 8 barbus. Now it takes forever to increase the population.
2° Barbu vers dodu
When you reach the max for each, the barbu are working too fast... or the dodu too slow.
By what i see, you need mor of two dodus for one barbu (about 2.15 or something like this).
3° Improvements?
- Make the storage a part of upgrades (capacity)
- What about a sawmill where the upgrades would be;
* Build new buildings (unlock)
* Buy "rare" essences with a great value in gold/wood
- sell (for gold) the stored wood. The value can be "random" each day (like a marketplace)
- Hiring "mercenaries" with the gold for a couple of days
- Include a salary for workers with the gold after a special event (unlocked by some upgrades)
- Graphically includes the upgrades. For example at one point if the speed has reached "8" change sprites to machines (trucks...)