Engine and Interface issues
I've noticed you run into the same issues a lot of Unity games have for some reason. So far there are no proper visual options and I have doubts about you getting really under the hood of Unity there. You need to make proper antialiasing code as well as actual support for DSR resolutions. Like many other games out there that use this middleware and fail to get the graphical tech part right, ending up in offering the very default of Unitys code. Which is sadly rather bad.
Second the UI systems feedback and some of it's design is bad imo. The left bar takes away too much of the actual game screen. Cascading the building options into it makes it even worse. It is good that you instantly get from ressource towards the actual building producing it, but not how it is done now.
The tooltips of many buttons as well as the game map tiles are bad. You have too much "on mouse over" shit happening, and tooltips clutter the space unnecessary. Why not relocate building/tile info into a separate window, preferably somehwere at the bottom of the screen like in traditional RTS.
There is also an issue with either the font you chose or it's antialiasing, since smaller text on lower resolutions is often hardly readable through it's heavy antialiasing with just so much pixels to smooth