The interface is beginning to show some scaling problems.  They are most obvious in city construction on the current build, but I can imagine them becoming a problem elsewhere down the road.

The list of possible buildings is really, really hard to read after any amount of research has been done.  The itty, bitty icons are awfully tricky.  I'd like to see a whole column at the side of the screen devoted to the possibilities.  Failing that, being able to access a separate list of possible improvements would be nice.