First of all, lets take a look at the original in-game UI of STRATEGA ( the 2D version of the game, highly inspired on the game Starcraft ).
and next, the in-game UI of the MOBILE version of STRATEGA
We can see that we have a LOT of info to show on the screen, sometimes that's cool, sometimes its not because it uses spaces of the game. I personally prefer the one that correspond to the mobile version of Stratega, the bad side is that we sacrificed the description of the structures and units and the possibility to do more actions with that structure (like sell or upgrade).
For the new version of Stratega, the following picture was one of the first mockups of the UI.
Then we decided to remove the TOP bar because it was using too much unnecessary space and moved that info in the bottom left side of the UI. The radar has also changed significantly and now it looks much clean and friendly...
The next step was to improve a little more what we got, we made some lines stronger, we combined the blue of the lines with another brighter one, and we slightly added more colors... finally we got these elements
Then we started to add those elements into the game... We've also changed the font, the font that we were using originally was Bank Gothic (used in Starcraft for example) and the one that you see in the picture below is Orbitron... the only thing that I don't like that much is the slash that have the 0s
And here is part of the in-game UI in action! We still need to add some elements.
The DESCRIPTION / INFO rectangle will be only visible when you click/select a structure/unit, or you have your mouse over one of the buttons to create a structure... with this behavior the player will have more visible spaces in the game (and I believe that its really critical for this game).