Was just thinking that a way to add a little more diversity to the game would be to affect the types of research planets can do.
Currently any planet can research everything one after another until all research has been done. But what if research was limited depending on previous research done before
As an example, split the research page into 6 fields, weapons, ships types, contructions, propulsion, etc
In each of these fields there are three researches possible for it, when you research one of them the other two disappear forcing to continue down that line of research in that particular field, the other five fields are unaffected until you research something in that field aswell.
So if we looked at propulsion you might have three available, Increased engines(makes your ships travel faster to defend in galaxy) Increased Hyperdrive(makes your ships travel faster to other galaxies) and Manovering thrusters(gives your ships a better initiative in battle)
If you reserached the increased thrusters then once complete you can only do Increased Engines II then III then IV etc as the other two researchs are no longer available. the same would apply to the other fields. Construction could have research's to increase the strength of building against bombing or you could go down the route of faster building times, or even to allow certain buildings to be available to build like spy centre's, then Finance, then etc.
The above is an example only so that you "hopefully" understand what I'm trying to suggest. Do not know wether planets should be allowed to exchange research with each other as it does make it slightly pointless if you simply can do that.
Would hopefully mean that each planet and race can be slightly different from each other and you can get into situations where one terran race is better than the other in combat purely because he has better manovering while the other did better thrusters for example.
Cheers
(ducks his head awaiting the inevitable critism)