I've been playing Sovereignty for a little while now.
Some improvements I can suggest:
1) UI Changes = If multiple nations declare war on the same nation on the same turn...give me one notice to join with all of my ally names not one for each.
2) If I try to upgrade a province that I don't have the money to upgrade, just play a sound after the first time. i.e. First time give me a popup with the choice of popups or a sound. After than, a negative sound saying it isn't allowed should be sufficient.
3) Manual could have a list of all army abilities. i.e. I was trying to discover which nation had armies with the scout ability.
4) Manual could have a list of spell powers by each nation. i.e. I wanted to know more about Boruvian spell tree when playing as Crivia.
5) The end turn button on the main screen is on the right, The end turn button on the battle screen is on the left. This is inconsistent. I prefer right.
6) Game has a memory leak, playing for more than 50 turns in a row causes a crash (not exactly 50). Find and fix memory leak and crashes.
7) Game crashes/won't load at all on one of my laptops, bug reports submitted.

9) More nation data. I feel like the interface is getting in the way of me understanding the data on each nation. After the start screen, I don't know what each one's goals are.
10) Getting back to your kingdom in the diplomacy screen isn't easy or intuitive. I end up having to close it and open it again.
11) Harbors are weird. Sea combat and moving is weird.