You could probably use standard vanilla mechanics, with a twist, to manage everything about Mars:
Open air becomes a kind of reverse water, needs a suit to survive in it. Enclosed areas can be filled with air, generally produced by earth plants you brought along.
Mars dirt is generally useless, but you can extract/compress/do something to make it into fertile dirt, for planting. Maybe a full stack of mars dirt has enough resources to support a couple earth-dirt tiles?
Compressors that allow you to store large amounts of breathable air in order to fill other enclosed areas.
Water is found underground (certainly a scientific leap but it must be assumed to exist, otherwise all you get is what you start with, from Earth).
Maybe the only thing that'll require a whole new mechanic is somehow "growing" breathable atmosphere without it being in an enclosed area. I don't know enough about the underlying mechanics of Minecraft to know how hard that would be. The default atmosphere shouldn't be able to support trees, but if you had a partially enclosed area with trees that are fed proper atmosphere, the atmosphere can slowly "leak" out and change the surrounding area, eventually allowing you to plant trees in unenclosed areas in self-perpetuating climates? It would need simplified a little, because the scale really wouldn't allow for that sort of thing in real life without it taking decades or centuries (assuming the resources even exist).