- UFO style disc
- Long body - like WW2 bomber planes
Different styles of walls - weak, medium, strong, or perhaps the research changes the way they look?
Gates - Not sure if there in the game, I've not come across them?
Plane Engineer for building on places where wheels and hover can't reach, - I know the mod has it but I would like to see it in the original game.
Solar panels/wind tunnels - For a little extra power
Laser guided Missile defense system, something to help shoot down long range missile warheads. Base defense only?
Suicidal cyborgs - BOOM!
APC - Armored personnel carrier - 55mm gun turret, fast agile light armored carries 5 cyborgs
Carryall - a plane that is able to lift single units
This is all I can think of, I hope I haven't mentioned things already mentioned

