Wow! I didn't expect so many answers so fast, but then again, I'm new to this forum...
I think all ideas sound great. I also have some new ideas, which are similar to some of the ones I have read so far.
But first, a comment about the Civil War. I must admit I am not too fond of the idea anymore. Such an event, or the threat of such an event, would just translate into a lot of micromanagement (build troops, build and move around ships, etc...), into a phase of the game which is already plagued by too much micromanagement. I think what we need is more like "now we have all these high tech toys, let's use them for something productive, besides crushing insects".
I think the Antarean threat could be turned into something nice. And maybe we don't need to introduce them towards the end of the game. (BTW, this is probably a stupid question, but what does "MEE" mean??? As I said, I'm new here..). How about this:
a) create a race with access to a unique and very powerful and essentially militaristic technology tree (superior weapons, fighters, armors, ships, etc.). Let's call it "Antarean Tech." for the moment.
b) give them a NASTY AI.
c) maybe deny them access to colonization technology (I've read about the Pirate&Nomads mod - could we just make them into some very powerful "Pirates"???)
d) find some way to incentivize the Antareans to conquer with troops (to make up for their lack of colonization tech.).
e) create a second branch of technology, "Orion Tech.", which can only be found in ruins, and which is very (only??) effective against "Antarean Tech." This effectively duplicates the Orion/Antarean storyline of MOO2, but we could create our own flavor to it. Ideally, the "Orion Ruins" would only be found on special planets, with the following characteristics: i) massively damages ships, ii) are hidden by storms, iii) anything else? Can we do this? I mean, is it possible to introduce a new type of planet with special characteristics AND that always contains ruins?
f) One problem here would be to create the "right amount of ruins". Ideally there should be only one such ruin-planet per game, and the ruins would give to the new tech tree. Alternatively the ruins could give just one tech, in which case we could allow many ruins instead. I guess the key question here is: can we tweak the probability of a special planet appearing? In that case we could aim for an expected number of such planets of 2. Assuming a bell curve probability distribution, my ball park estimate would be the following probabilities:
- no Orion ruins: close to impossible
- 1 ruin: low chance
- 2 ruins: high chance
- 3 ruins: low chance
- more ruins: close to impossible
The idea is to always have at least one ruin.
g) in writing that Last point, I got another one
Why bother with these probabilities? We could just create a certain number of "Orion techs" that are all cery effective against Antareans, but with very different strategies, e.g.:
- one "fighter" tech
- one "planetary defense" tech
- one "troop" tech
- one "planetary attack" tech
- one "ship weapon attack" tech
- one "ship defense" tech
The idea here is to add uncertainty and decrease the possibility the player has to "prepare" against the Antareans. In two different games, the player would have to adapt completely different research strategies, depending on the Orion techs he/she has discovered so far, tryin g to "compensate" with regular techs in weaker areas.
All of this would have to be calibrated so that the Antareans start out by being just a nuisance in the early game, but as they grow stronger, they eventually constitute a Great Enemy in the latter part of the game.