My last game was 18k points.. unfortunately it didn't save the game before that which was 14k pts. 

Didn't MoM have a high score list and gave teh breakdown for the points?  Would be nice if we a) kept prior scores (maybe per victory type?) and knew what made up the score.  Retirement should also give a point score other than "Janusk"

I think that the score might be calculated as [(faction_population) + (4*time_remaining_for_victory) + (something_else)], where time_remaining_for_victory is calculated as (1000 - turn_number). something_else might be bonuses based on what victory types you had, or the difficulty level of your opponents, or something along those lines.

However, the above is a guess - I'm not sure that that is how it is calculated, and I don't have a large enough sample size to determine if that really is about right or not.