Visit the acidic world of Muria, where the air itself hates you.
Mods introducing new content into the game.
New places to build more factories.
Augmented or new ways of transporting materials - belts, inserters, pipes!
New ways to deal with enemies, be it attack or defense.
Map generation and terrain modification.
New Ores and resources as well as machines.
Things related to oil and other fluids.
Furnaces, assembling machines, production chains.