The gravity of the planet could affect the energy costs

[Zequez]

So, I was thinking, to add variation to the level generator, each map could have a gravity constant that could affect the energy that all the machines use, so in a low gravity planet you would need less energy to run the operations, while in a high gravity you would need more.

[ssilk]

Hm. My realismn-nazi comes through: a planet with the gravity of Mars isn't able to hold the water, while a planet with more gravity doesn't loose the hydrogen hull and ends up in a mini Jupiter.
It has a reason, that the Earth is exactly this size.
I've more reasons but stop here.

[Drury]

Seems a bit out of Factorio's sci-fi hardness scale.

Besides, it seems all maps are generated on the same planet inhabited by the same species of biters.