An interesting and promising concept, but:
- It would be nice to add a tutorial or at least some minimal intro to immerse the player into the process
- It would be good to add explanations for each icon and text choice, because it's quite difficult to understand what resources are needed at first
- Fix the overlapping of sprites. There is an issue where you can't select a specific character if you create several characters at once
- To make it pleasing for both the eye and the ear, you could add animations — at least for buildings. You could make a few static images with different visual lines to keep the style, and add at least some background music
- Add a clear goal for the game and a few more buildings so that achieving that goal is possible through multiple paths