I keep getting little visual ideas that I want to jot down, so here they are.
In Hardwar ships can't leave the craters and sort of magically stall. Perhaps this can be addressed by coming up with a repulsor-drive system, where the drive is set to different altitude tiers. It becomes prohibitively expensive to go higher due to how the whole repulsor techomagic works. Going closer to the ground means the drive can grab onto something and is more focused. This makes control during dogfights a bit more complicated though as the pilot needs to both set speed, angle, and altitude. But it's also more unique compared to other games... a thing to control which could add a sense of mechanical realism.
In Hardwar the ships aren't actually like airplanes though, They can't roll or angle freely. This suggests to me that there's some kind of antigravity thing inside which sits in a cradle with limited movement, so I'd imagine something like that for my repulsor variant.
I found an old interview mentioning the water in Hardwar... it was supposed to reflect the orange sky, but they deliberately changed it to water-blue... so apparently it is water? Which means the green might be plants and there has been some terraforming happening over the centuries. There are actually some terraforming-specific buildings now when I think of it. I haven't played through the game or looked at the FMVs and radio messages. This game barely has any net presence so it's hard to research.