Here is a few somewhat gamebreaking issues that are still not solved as of in TOA 2.02, though they have been brought to the table back in the summer already.
Issue 1. After playing for a while, Weapons technology suddenly increase in cost by a factor of 3.38.
Isssue discussed here: https://forums.galciv2.com/311639
To exemplify (playing as the Iconians)
Mass Driver Theory cost in rp:s:
Early in the game: 10 turns (22rp:s/turn) = estimated 220 rp A little bit later in the game: 5 turns (149rp:s/turn) = estimeted 745 rp
(reserach cost has suddenly been multiplied by a factor of 3,38)
Kinetic streams II cost in rp:s:
Early in the game: 13 turns (34rp:s/ turn) = estimated 442 rp
A little bit later in the game: 10 turns (149rp:s/ turn = estimated 1490
(researach cost has suddenly been multiplied by a factor of 3,38)
The sudden increase in tech-cost does not seem to affect defensive military techs.
Issue 2. Some races do not expand beyond the orginal shpere of influence. (Theese tend to be the evil races)
Discussed in many threads - here is one: https://forums.galciv2.com/326874
After installing 2.02, I have now played 2 games after my half a year break from playing. In both games both the Drengins and the Yor refused to expand. During the second game I payed closer attention to the Yor who only had 4 planets in their starting corner and the only possible colonization direction for futher expansion was through my space. How it happened, I had several high quality barren worlds whitin my shpere of influence (worlds, witch the Yor can colonize from the very beginning) yet they never did colonize them. (Yor can hardly even be culutrally subverted so even this would not have been an issue)
Why do some A.I:s fail to colonize?