An overhaul mod focusing on end-game technologies and moderately increased complexity.
Large total conversion mods.
Transportation of the player, be it vehicles or teleporters.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Trains are great, but what if they could do even more?
New ways to deal with enemies, be it attack or defense.
Armors or armor equipment.
New Ores and resources as well as machines.
Things related to oil and other fluids.
Related to roboports and logistic robots.
Furnaces, assembling machines, production chains.
Changes to power production and distribution.
More than just chests.
I end up building gigantic fields of hundreds of gasp power stations. This is kind of unhandy and unrealistic. You could maybe add a big gas power station. Factor 100 more gas or so.
Pretty sure you're supposed to just move past gas at some point, just like steam.