Establish dominance by having your Vulcanus drop pods land on Demolishers.
Small changes concerning balance, gameplay, or graphics.
New places to build more factories.
Transportation of the player, be it vehicles or teleporters.
New ways to deal with enemies, be it attack or defense.
Changes to enemies or entirely new enemies to deal with.
Map generation and terrain modification.
Not much to add, just wanted to point out how cool the idea is, and how great the execution is!