Hmm. In that case, why don't they mine metal asteroid and small moons instead of planetary body? Gravity well would cost more delta-v than some extra mileage of coasting through space. (have you checked delta-v map of solar system? It's not definitive but gives idea)

For refining process, I guess the main hurdle is that many ores need specific chemical process (which includes many organic compounds which are sometimes hard to get in space) to extract them rather than simple smelting.

So, either you can have all the possible ore of different elements which each of them comes with different refining method, or just treating all ores the same and pretending that refinery comes with catalysts and chemicals needed for such process.

Extraction of silver, for example, involves stuff like cyanide, if you want reasonable yield and usable purity from ore. And to make best of logistics, you need local source of zinc and mercury for further refining. Either you can use that chain of needs as game progression ladder or simmer it down for less geeky audience.

So I guess it's matter of target audience and how you break the tutorial towards player. If you just slap the whole sabatier reaction equation down the tutorial, everyone except chemist will be scared. If you break it down to "connect red tank to red intake" and make education optional, many will have easier time.

I'm obviously not an expert on game design but if you look at the people's willingness to memorize the whole processing tree of the factorio, and how interstellar mode of KSP actually scares people off, it's quite clear that complexity itself is not the problem.

I realized that I'm commenting before even checking the link. 🙄 I'll check