Today's screenshot speaks for itself:
I did a bunch of optimization work last night, primarily reworking the way location and feature data are structured and indexed. Once the major gains had been made there, the remaining slowness was all related to the way I was doing tile graphics. Since I'd been interested in taking more of a vector-based graphical approach anyway, I decided this would be a good time to take some steps in that direction. The results are above.
Things may get even more neon from here on out. The game runs quite a bit faster now too, which bodes well for my further efforts.