Tech points can also be gained by certain events. But I'll usually play my games to get the 3rd level medicine before the 3rd level fertility to extend my villagers lives.

Also remember that with mushrooms people can "cheat" by placing multiple kids on one mushroom.

Maybe you should base your ranking system on how much food is collected? Even when an event wipes out your food supply, that number keeps increasing as long as the game is "running", even in background mode.

Or possibly how many triplets are born?