Lovely art and I like how voxely the terrain looks. Having the minimap in the bottom center looks good for an isometric perspective.
Interesting concept from the scene with the animals on the start screen, some sort of magic energy cocoon is healing(?) a wolf.
I really appreciate you providing the source code as you've made an impressively solid base for an RTS made in Godot. I've been meaning to learn how to use Godot but haven't come across many RTSes written in it yet so your project will be a great help! :D