It´s already a cool tool.
But i wish some things to be added:
-trees, palmtrees, bamboo
-all kinds of flowers
-pumpkin-plants (all four colors)
-the airport
-the sea-bridge
-a custom-design-tool inside the path-tool, that opens a file-chooser-window to load 32x32 pixel png graphics from pc for placing as path on the ground
-a file-chooser-window to choose a custom location on the pc to save or load map-files