Yeah, the Armageddon counter is really is a good idea, there got to be a point where the moon will be destroyed, and we do need to borrow or make some new terrain to place in the map to tell how much the moon is taking damage.
We do also need some natural happenings, something like that plague they did on the total realism mod, and make a different natural happening, meteorite hits... the moon have been hit a lot with these rocks, and it still protects the earth from them 80% of the time, now all we need is to add that in the game.
Once the meteorite hits a terrain, that terrain will become unusable till 20 turns, after the 20 turns, the land can be used again. If there is a city that got hit, it will take a lot of damage (building losses and populations only).
Now we need to set up a different space race on the game as well, change the name of the space race to Mars Colonize. More infomation later.