Hi! I think this game is very intersting, here are some things I thought could be improved:
- Buildings that aren't built yet could be transparent, and if the action is cancelled they need to disappear. It can cause confusion and leave the player repeately clicking the 'phantom' building in order to upgrade it.
- If the mechanic is mining red and blue crystals, a slider to change mining priority would be better gameplay than clicking them and assigning workers. Try the slider node on Godot, just be careful to select correct signal. One of the signals is emitted every slider change, so when the player is controlling the slider, all hell break lose while the same function is executed too many times. It's fun tho!
- More information about buildings is needed, efficiency is not explained enough.
I like the idea very much and I'll be sticking around after the jam to see updates. Good work!