A mod that automatically deconstructs toggled ugly 'natural' structures (rocks, cliffs, trees) in the way, as you or your bots place beautiful, industrial concrete. Can toggle rocks, cliffs, and/or trees, if you wanted to do that for some reason.
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.
A mod that, on placement, simply forces vanilla lamps to be always on and white.
Small changes concerning balance, gameplay, or graphics.