I like the city style but would like to see more variation, unless you're going for an iconic thing (by this I mean pic x=metropolis, y=city, z=town). Time is short for these entries I guess but it'd be cool if you could sort of come up with a little flavor for each city and make the icon slightly different. Just a thought...and probably a time-consuming one at that!

Maybe a little more shading on the forest canopies? At first I mistook them for grassy mesas. The green looks to me more like a flat layer of vegetation than treetops. Now that I look at it again, maybe the suggestion of treetops (with squiggly lines or whatever) might be more useful there than just shading. I think the strokes just inside the border partially led me to misread them as landforms rather than trees.

Looking great!
M