[LoloMo]

From my experience, games where alliances play a big part, like the two megagames, tend to be a bore when you get into late game. To do well, you need to spend hours on diplomacy which takes the fun away after a while.

How about a mega game where diplomacy is minimized? Turns can be played much faster with less agonization. I don't know how rules can be set to minimize diplomacy, perhaps something like:

1. You have to declare war on a nation publicly before you can attack that nation. You can declare war on the same turn as you script to attack.
2. There can never be a ceasefire. War, once declared continues until one of the combatants is dead. When a nation is eliminated, the winner has to declare it publicly. A nation that goes AI still has to be eliminated.
3. You can not declare war on any other nation if you are at war.
4. You can not declare war on a nation that is at war with more than 1 nation. (So a nation can be at war with a maximum of 2 nations only).

A lot of diplomatic energy is geared towards ensuring that you fight only one nation at a time, so the above set of rules would simplify or eliminate diplomacy.