Nice feedback thanks, any ideas on how we could solve that withou text? Maybe a red effect on the resources or something when pressing the build button?
A common way would be to show what is required and highlight the still missing parts in red. That could mean that you show the base icon with the necessary resources (x trees, y stones) and color the missing resource in red. Or in case of the converting, a red base could be shown. Although this would not solve all problems.
At some point of time the game must communicate, what is the goal of the game. For a jam game the simplest solution is a wall of text.