I've never gotten higher than 50% culture spread at the end game chart, despite having culture buildings everywhere in the galaxy, seeing my lines everywhere, etc. How to get 75% achievement? Or is it bugged?
I personally found the missions quite fine. Yeah, the objectives can be annoying sometimes. But after you complete two missions, you can usually set up a cease fire. And two missions more and you will likely have an alliance. I find the alliances quite handy, as the AI is quite helpful and won't necessarily ditch you. You can fail about two missions max before your alliance might end, giving you leeway for keeping relations up. Don't forget you can issue orders to the AI to help attack
