I like the theme. The concept of harnessing power from the old saying of having them turning in their graves is wonderful. The game has a nice supportive message. I like that you are building up the community and the building gets added to as you progress. Unfortunately, there really isn't much of a game here. You could add some additional mechanics to let the player have more to do.
It would be nice if the game scaled and had a full screen option. There is a fair amount of black borders around the right and bottom sides, so I'm assuming you don't have scaling enabled. Godot has built in support for auto-scale that you can set in the Project Settings.
The text can be a bit hard to read. It would help if you darkened the backdrop for the text to give a bit more contrast when the background under it is brighter, such as the top area. Similarly, adding a backdrop to the text of the the ancestors would help with its readability.