Below 100000 O2, 10000 Pascals, 150000 water and 200000 mk will result barren and plantlife will don’t survive. When you reach plants can survive, But is hard. The best goal for the terraforming Mars is oxygen, but fastest thing is pressure. Some sites found Mercury has most oxygen in atmosphere (49%), But no planets in solar system oxygen atmosphere is 50%. It's almost no atmosphere it's impossible to be have a oxygen. I found a bug, Venus atmosphere is similar to Earth.
