New places to build more factories.

Transportation of the player, be it vehicles or teleporters.

Augmented or new ways of transporting materials - belts, inserters, pipes!

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.

New Ores and resources as well as machines.

Entities which interact with the circuit network.

More than just chests.