1. More factions!
What is an expansion without more factions?! There are only eight factions shipping, but world is so big they could add at least eight more factions in DLC alone! I wouldn't mind playing a Buddhist-Corporate-Shinto mission to le Planet!
2. Floating Cities!
Why stop at just underwater cities and sea cities!? They could add cities that float in space on the space layer! This would open so many new mechanics and expand the very shallow and satellite system that currently exists. More layers=expansion opportunity.
3. Converter!
The le CK2->EUIV converter for Paradox was super cool and I think that could work for this game (V->BE ofc lol). The starting situation would be based on the civilizations, religions, victory conditions, economies, politics, trade deals, and eerything else from that game into the new one! A grand campaign from 4000 BC to 2500 AD!
4. More Affinities!
There are only three affinities? That's so lame. It doesn't even sound like it would play right, so I think there should be more affinities. Maybe sub-affinities! They could have sub-affiniites!!!
No but seriously. Sub-affinities.
5. Aliens?
Aliens.
6. More units and techs!
We need more units and techs! A tech that unlocks time travel so we can send units back and time to invade ourselves or something! But seriously, of course we'll get more techs. As always.
Three space layers and a time layer! It would be revolutioanry! only one game i know has done this, but i cant remember what it was called.
What do you guys think? I think a time layer would be really cool, but I can't see how it could be hard to work in. The rest? All of it seems totally doable, including floating cities/space stations. Then again, I am relying 100% of what I've heard since nobody has played the game and therefore knows exactly how the space layer works (I've heard conflicting things). As for aliens, well, what more can be said? Aliens. Lets not overthink it.