Here is the issue:
1. The beginning of the game is extremely fun. You're constantly thinking: what's the best method to get the most colonies? That's a challenge.
2. When war begins, that part is fun too. How do I not get owned by the AI on Suicidal?
However, there are two patches where the game gets EXTREMELY boring:
1. The period BETWEEN the colony rush and the beginning of war. Due to the way the pop mechanics work, you simply CANNOT invade your neighbors because your worlds don't have enough population and production. The AI is in a similar bind. In this period all you're doing (literally) is building factories/research buildings and constructors. That's it. You aren't doing anything else. You CAN'T do anything else.
2. The period AFTER you've attained dominance. There isn't a challenge anymore. The rest is just mop up until the game officially says "you've won."
The larger map, the more painful those two boring patches become. So.... thoughts on dealing with this?