TL;DRUsing different forms of industrial waste as a weapon and\or seriously raising difficulty levels
Making more waste intentionally
What ?I have read this topic viewtopic.php?f=80&t=21278
and haven`t found general idea of using complete opposite of "being clean&green" playstyle.
The idea is to have 2 main playstyles. let them label as "good" and "bad" to simplify.
"good" way is using solar energy, containing pollution and so on.
"bad" way includes using solid, liquid, gaseous and highly radioactive waste alongside with agressive liquids like acids, as a weapon against aliens.
As an example: using radioactive waste to form nearly impassable zone with lethal radiation levels or constantly contaminate area with corrosive waste gases for similiar reasons.
Additional difficulty on this way could be spikes of alien evolution(especially mutations due to excessive use of nuclear power\waste)