Thanks for playing and for the feedback!
Yeah the camera needs polish. It also jumps when the mouse leaves the canvas. At the moment I calculate the camera location based on the mouse position, but it really should be a stored location so that its movement can be smoothed out and remain in position when the mouse leaves or when you bring up the map. That would also allow zooming smoothly between the main view and the map view.
For the upgrade system, I actually had a scheme that made it more obvious from the first upgrade but I didn't like how that looked and changed it last minute. I have an idea now for how to make it work both ways.