Well, I congratulate you as this is a great project, I'm more than sure that you have learned a lot while doing it!
I know how hard it is to build a GUI, but it is mostly fine as it is (except the artistic choices as I said 😛). Themes are a very powerful toolset in Godot, I've also used them for my project and it saves a lot of time if used correctly.
Great job! 😁