Premise:
If I try to win a research victory in Gal Civ 2, everyone tries to obliterate me right before I achieve it. Why? Because as soon as I win, everyone else loses. So a research victory is really a research/military victory. It never comes down to a pure research race.
But the game doesn't need to immediately end, does it? What if everyone else didn't lose as soon as I won my research victory? What if only other people shooting for a research victory were defeated? Things could get a lot more interesting. I could try to placate the Yor with treaties and free technologies right until the end of the game. It is no longer a certainty that they will try to destroy me. Possibilities for cooperation would be much enhanced.
In this post, I'm going to put forward a design for a new game mode that presents some interesting game play possibilities by creating assymetric winning conditions.
Design:
1. In the game lobby, allow players to choose objectives from a list. If two or more players choose the same objective, they are pitted against each other (only one may win out of that group).
2. Each objective has its own defeat criteria. While any player will clearly lose when all of his her or cities/units are destroyed, there may be additional criteria as well. For example, in an Economic victory, a player may lose at any time if their gold reserves fall to 0. If you were pitted against this player for an economic victory, you could defeat them by bankrupting them.
3. When a player completes his objective, all other players with the same objective are defeated, but players with other objectives keep playing.
4. Sample objectives:
a. Economic - Build income of x per turn, collect reserves of x gold
b. Diplomatic - Collect x vassals, collect x treaties
c. Conquest - Control x cities, control x earth nodes, allied victory
d. Research - Discover technology X
e. Quest - Complete the quest for x, defeat x monster
5. The problem with this game mode as I have currently conceived it is that players that have won or lost will then leave the game. The question is, what do you do then do with their empire? And how do you keep the game interesting with fewer players? I have a few draft solutions, but this issue will definitely require more thought.
a. The most obvious solution is to have the AI take over for each of these players (if the AI is less than superb, this will make the game less interesting after someone has won).
b. The winning player has already "won," but can stay in the game to try to influence the outcome of he rest of the players, perhaps with new powers.
c. A massive random event occurs that eats up the players that have left (e.g. for research victory, defeated players' cities become undead, winning player's cities become enlightened). However, the random nature of this has the potential to just become a RNG...)
d. Transfer the assets of the losing players to the winning player and give him a new objective.
To avoid enlarging this wall of text, I'm going to avoid delving into all the gameplay possibilities that this game mode would present. Rather, I will conclude by asking a question: what kind of gameplay possibilities do YOU see this game mode creating? Fire away. 
