For me AI War, after release of the first super-cool expansion, become a some kind of "Diablo+RTS mix" where your army and your technology tree is growing over time, you find the new "artifacts" (the new ship technologies) and new "weapons" (zenith golems), and every game session was always different due to resources, technologies and factories you found - and this is the really good experience this game is providing (in couple with the epic AI i never beat even once)...
Maybe, to make this impressions more memorable, you can add something like a achievement-based customisation system that will increace the replayability and allow the players to change their playing style or at least appearance between games (something like new colors, skins for the ships or even another 3D models) - then, after the longest campaigns, you will get a tons of completed achievements, and with them - new features and bonuses...
As example of customisable feature: players can get the "starter squad" before launching a campaign - this is not affecting the balance in the mid-late game, but allow you to work with your favorite playing style from the beggining of the game and allow you to play vs harder AI than you was able to play before (and also you can get some favorite heavy ship which will be your core unit for the first hour of playing before you learn how to create this ship by yourself). Number of the ship-classes you can choose from is based on the number of achievements you finished already (something like: "If you finished the quest of some human faction once - you will get the access to the human flagship as starter forces for the next games" or: "Take the control over factory of Fighters mk5 to get the access to the fighters as starter forcess for the next game").
Squad size can be limited by the number of the resources: player getting 100.000 of metal to buy units for the starter squad, can buy some number of mk2-3 units without technology for buying them and as result, for example, player picked 30 bombers mk2 for the start and spend all the knowledge for the fighters and cruisers - so he have a big amount of high-lvl ships and this 30 bombers will be a good addition for the start!
Another way for limitations and balancing - developers can create the squads by themself and player can get the access to this squads through achievements, so achievements can be like:
"Complete the campaign for the human faction to open "Showel" squad as starter forces:
- x1 Flagship mk2
- x20 Bomber mk2
- x20 Fighter mk2"
"Build 10.000 fighters in total to get the access to "Fighter" squad as starter forces:
- x50 Fighter mk1
- x40 Fighter mk2
- x30 Fighter mk3"
"Steal 1000 units from the AI to get the access to "Thief" squad as starter forces:
- x20 Parasite mk2"
This starter squad feature will be interesting with possibility of taking "humanity" squads for start as "zenith" or "spire" faction, and making the combo of squads with another players in multiplayer! For additional balancing there can be options for "starter forces scaling" to get 2-3 times bigger forces for playing vs 10-th dificulty lvl AI or just to remove this starter squads...
Another way of customisation is starter ship-technology bonuses - you can choose one additional technology from the list of technologies you already opened for yourself in the previous game sessions (but some of technologies is too epic for getting them in the beggining, so not every of technologies can be available for start with).
When you will make the "Champions" for AI War 2 - you can allso make them customisable between games, even make a ways for players to paint this champions in different colors and opening some unique "sub-factional" modules (or even greater idea - all of this champions is sub-faction based, so for every of sub-faction's achievement player unlocked he will get the champion-ship which belongs to this sub-faction!)...
The whole point of this achievements is to put the game process over game result - player will enjoy the results of his unfinished or failed campaign because anyways this playing had some point, and such leveling of his customisable parameters will make a some kind of connection between all of campaigns player ever played... But in the same time it is important to keep game balanced and do not force players to grind for the achievements to get some advantage over AI, and not limit the possibilities of player who not want care about all of this little objectives - so this is the reason why customisation have to affect early game and appearance mostly.
If this idea have a chance to be added in Ai War 2 - we can think there about of all possible achievements and other kinds of cutsomisation bonuses.
I hope my epic english was not too hurt for read... x'D
