Suggestions: from my friends and me...
would be nice if not only the design would change. we play a lot of experimental mode and wait for new ones things.
I hope you like it? 
Vehicles for 2 people - Multiplayer Mode
Wave attacks and pollution indicator of the world - the more dirty the more aliens or the more radioactivity the oftens an attack.
Gun Turrets with conveyor belt connection for ammunition.
Teleport Gate - built from the WIPs (Entrance - Mercer-Späre WIP + Aluminum Sheet (50x) + S.A.M Ingots 100 + Super Computer) and for Exit (Somersloop WIP)
New parts for the space lift - Aluminum Sheet 10.000x - quartz oscillator 1.000 - Electric control rods 500x
New Ammunition - Full Metall Jacket (the old ammunition is Yellow the new with Full Metall jacket Red )
accumulators for clean electricity - a central distributor with timer on day - night. Or when the battery is full the power plants shut down.