1. Many more planet types with various conditions like in galactic civilization 2! (There are: Vulcano, Desert, Earth-like, Arid, Rocky, Plains, Non-atmosphere and so on).
2. The ability to terraform planets. To change ice planet to thriving green planets.
3. Various events, like electromagnetic storms, earthquakes and such. Planetary collapse! Good and bad events!
4. To be able to build a research outposts or something like that in non planetary regions like Debri fields, gas giants, wormholes, asteroid fields. And ofcourse in planetary regions aswell
5. Lesser planets in one solar system (5-15 planets MAX...), then some asteroid fields and such...
6. Binary systems!
7. A new race!
8. Defense buildings to be more effective!
9. Phase inhibitors to really stop the enemy from fleeing... They should have to destroy it to get away
10. More ships
11. A campaign
I would love to see most if not all of these thing in Soase expansion or the second game:D