I have a few ideas so please excuse the large reply. I do think that most to all of these would make the game much more in depth. GO TO SUGGESTION 7 FIRST- IT IS THE ONLY ONE I TRULY FEEL NEEDS TO BE IMPLEMENTED. The rest just would make the game much more fun in my opinion.
(1) Possibly creation of planets or even stars? Obviously it would be a very late game tech. personally, I don't think incorporate a leveling system like how Archcreature(Reply 12) described it(As it seems a bit too unrealistic for my taste) but that's just my opinion.
(2) Possibly make disease relevant. Maybe make disease kill off population at a slow rate on infected planets(just enough to counteract the planet's growth in the begging) then eventually get bad enough that large chunks of the population die off every turn. You can add techs to prevent and slow, then even stop all diseases. Some diseases can even have things that modify other things (Fungal infection that slows population growth even more, Arthritis like effects that lowers production, brain tumors that lowers research, etc). Also, I think disease can be transmitted via trade route and throughout your controlled planets slowly. Diseases should also appear randomly like an event. This would make the game much, much harder so if it is implemented you should probably give the player the ability to turn it on or off at game setup. Possibly make it disabled by default and suggest to only turn it on for a more difficult game only.
(3) Not really much of a suggestion but possibly capitalize the star names sent in by the founders?
(4) As Archcreature said in reply 10, add in the ability for your agents to counter enemy agents from stealing tech(If tech stealing will exist in the game) and hiding trade routes and other information from the enemy.
(5) Add the ability to cull half your population. It seems violent but that seems like a good way to get rid of those extra 5,000 colonists for those who are too lazy to research the techs that increase your pop's happiness. It would make sense for the Drengi. It should increase happiness in the planet, but decrease the rest of your planets' approval. Or possibly just make everyone unhappy.
That one isn't going to make it in, is it. Oh well.
(6) Racial unrest? Say your playing as a Drengi and take over Altaria don't you think the Altarians living on that planet would be slightly enraged? It seems very unrealistic if they suddenly being acting like Drengi. Maybe put a racial modifier to the approval and list the majority of the population on the planet's race. Only certain races should cause problems. Like humans taking over a Drengi planet should cause more unrest on the planet then Terrans buying a colony from the Altarians. And if you took over the planet there should be a penalty for that planet, at least for awhile (Ex: 25 turns).
This seems like it would be a lot of work and could cause and have a lot of bugs so I wouldn't be surprised if it isn't added. It also seems as if it would be very confusing.
(7) I NEED this one: Rebels! If this is already planned, at least look at the suggestions for mechanics at least. If a planet's approval gets too low a planet can secede and create it's own empire. Maybe all ships stationed on it can also become part of their empire and they get 3 new ships when they secede. Once they secede the player they left automatically goes to war with them. If the player's capital secedes then maybe just make the capital move to the next planet if they have more then just one planet, of course, you could always make it be changed in a menu or just make you strait up lose. They can function as if they were just any other major(or minor if you would rather, but that would make it less fun.) except much more hostile than other races towards the player. Maybe make it to where they have a relationship modifiers(or whatever those things like "We are trading with you" or "We have common allies" are called) just for them that's called "We rebelled from you" or something like that, and probably make it 3 minuses(or 2 if you are feeling lenient). You can also make it to where if there is nearby rebellion groups and a planet secedes it joins that group. You can also make it to where when two groups rebelled from one people (such as two groups rebelled from you on the "north" and "south" part of your controlled area and break strait up through your "center" and meet up the two groups could join up with you and merge your existing war (That mechanic seems like it may cause a few bugs, but it would be very cool). You would then have one, twice as large, twice as strong enemy going strait down the center of what you used to control. Like I said before they should act as any other major civilization, so they can obviously go into war or even ally with any other civilization. They should also be able to call in allied civilizations into the war against you(or another group's rebels calling you into their war). They should also be able to win the game through the enabled settings like any major civilization(obviously). They should also be able to colonize new planets like any other civilization.
This defiantly needs to be implemented(or at least rebels of some kind). In our history many nations were created by rebellion (Such as the US, a small nation spanning from the Pacific to the Atlantic oceans taking up nearly 4 million square miles)
(8) Terrorists and Bio-Terrorists. I think terrorists should be hired by going into where ever the espionage tab is and clicking on the hire Terrorists or Hire Bio-Terrorists. Terrorists should cost 5,000 bc(To counteract their power) and kill 2,000 people, and have a 25% chance to destroy 1 building at random. Bio-Terrorists should be 7,500 bc in my opinion, and kill 5,000 people, and release disease(If you implement my idea of disease then make that a way to get it, or if you don't, just make it a modifier to the growth statistic of that particular planet. There should also be a 50/50 chance that the civilization who you attacked finds out who sent the terrorists and declares war on you(If not already at war).
If you implement this I will turn the Terran Alliance into the space ISIS
(9) Pirates mechanics. I know pirates are a planned feature so I am just going to suggest what I personally think the pirates should be like. Pirates should have one pirate space station that 3 to 10 (usually 3 to 5) ships attached to. They can also sometimes(but rarely) have planets under their control. Also, you should make pirates from different stations(or planets) sometimes fight. Each pirate ship can only be linked to one station, but one station can have up to 10 ships. You cannot trade to talk to pirate ship, but they attack your ships and trade routes. They do not attack planets(As that would make it very hard for minor civilizations). They also do not make constructors, freighters etc.
(MAJOR BUG) My game freezes and I cannot interact with anything on the screen. These happen very often and the frequency of the freezes have been increasing. I have been closing the program once it freezes with task manager so my crash dumps might say it was closed because of task manager or something like that. I have 8 gigs of RAM and an i5 processor so I doubt that's causing it. I also have a new graphics card with updated drivers (I bought it earlier this year and updated the drivers 2 days ago).
Linked to folder. Message me if this link does not work
The most addictive strategy game ever (Apparently, strategy games can be addictive). All it needs is for the freezing to be fixed and the Beta would be fun for more then 30 minutes