Well, GalCiv2UE is great, but for GC3, I'd like to see the following:
1. A change in file types: .X, .XML and .PNG are all great, but there are better file types out there, I suggest the use of .TGA(compressed), .INI and some other model type that can be re-opened in blender (.x files can be exported but not imported.).
2. Don't forget the little guy: Even if it is a newer game, please don't forget most people cannot shell out $800 on a new PC to run the game, so I suggest the use of DX 9.1 minimum(compatible with old GPUs.), dynamic loading*, and a new compact game engine(or a compacted upgrade of the current one...).
3. Modifiability: GC2 was a game changer in the mods department, as it allowed almost every aspect of the game to be re-done by the user (a highly rare and valued trait), I think that 99.9999% of the game should be able to be modified, leaving only the game engine and a few hard coded values locked away (leave as much as possible changeable, even the GUI and AI, perhaps even the game mechanics).
4. Remove the .BIKs and add in their place use Quicktime RLE to play back things.
I. Bloom lighting(on/off, 1-4 detail quality)
II. Bump, normal and UV Mapping(on/off, 1-4 detail quality)
III. Planetary Atmospheric Quality(On/Off/Legacy** 1-5 detail quality)
IV. DX Version (drop-down menu with installed and supported DX redists)
V. Map Rotate Snap (On/Off, toggles the right click rotation snapping back to default)
6. Evolutionary gameplay (AI learns from mistakes, attempts to correct issues, tries to solve problems, asks for help etc...)
7. Colonizing minors (Moderate colony cap, star bases less prioritized.)
8. Ingame tech tree viewer(assists with modders breaking techs and not knowing until they load a game.)
9. Smart AI (AI knows what to place when there is a tile bonus, utilizes planets to the fullest, and will attempt to balance their budget.)
10. Adaptive Galaxy (Random events can change the game in the favor of no one, everyone, one or two player, etc..)
(Ex: Star in #,# goes super-nova, star systems within 1 sector are gone, star systems within two have all planet classes dropped 5 points. Star in #,# sector cools off, worlds closer to it become habitable, those further out freeze or loose planet class and # random improvements.)
11. Dust. No really, I'd like to see large clouds of dust, gigantic nebulae, molten worlds trailing dust and debris
12. Planet orbital mechanics (planets orbit their star a set amount per turn, orbital period, circularity and inclination randomized within real world physics)
13. Stars with realistic colors, temperatures and planets (Stars that are White -> Blue are too hot to be colonized closer to the star, Red -> Yellow are uninhabitable at large distances from the star, asteroid belts form randomly on galaxy gen, no green or purple stars, realistic light values to the stars(red produces red tinted light, blue produces faintly blue light, star brightness and temp randomized, temp determines color, temp can change randomly.)
14. Local gravity determines speed (ships near a high-mass object slow down as the escape velocity of that object climbs, stars can die and form with either a neutron star, pulsar, magnetar, or black hole, black hole slows ships to 1 Pc/wk, black hole destroys ships within a 1/4 of a sector from it, black holes have halo of bent light around them to show it is there.)
15. Galactic shape and mechanics (galaxy rotates at an insanely low speed, always a black hole of varying gravity in the center(to compensate for smaller maps))
16. Ingame map editor.
17. repaired custom ship style creator
18. more diverse mega, minor and super events.
19. custom super-ability editor
20. Disaster can strike planets or even whole systems, mega even style options for good, neutral and evil.
Sorry for the minor text walling here, just some ideas for SD to consider if they even read this.
*-Dynamic loading would unload anything not used, and allow for more objects on screen at once.
**-Legacy support for the clouds.png from GC2.