I'm probably late to this, but I originally posted this in the wrong thread so I figured I might as well move it:
As for the HUD, having played around half a dozen games or so (and a few 1 or 2 turn failures), I'd at least like to see the following elements on a city HUD (I would imagine they could be turned of if a player doesn't want them cluttering up the screen):
- City level
- Room left to grow in tiles
- Amount of prestige
- Icons of resources gathered in this city (maybe amounts too, not sure)
- Perhaps a visualisation of the unit being trained, if any. Maybe also an indicator of the remaining queue. Maybe total turns left to build the rest of the queue or something like that.
- Maybe some kind of visualisation of the strength of the defending units. Perhaps their combat score? (as seen when inspecting NPCs)
I think this would make for a really nice experience when macro managing a number of cities. I am a big fan of the BUG mod for Civ 4 ( http://civ4bug.sourceforge.net/BUGMod.html ) which gives you quite a bit of this sort of information in the main screen if you want it - perhaps a good place to look for some inspiration?