Up and Down

After importing the updated maps generated, I went ahead and updated both automatic Z traversal (ramps) and queried Z traversal (stairs):

I'm going to really need to change some of the tiles, for example, when you're up on the highway, it's barely visible that you're not still on ground level.  Either that, or greatly increase the darkening of terrain below you.

Anyway, time to clean up the interface a bit so it looks more like an actual game, then move on to implementing inventory, creates, etc.