[Suggestion] Another kind of Hard - Sparse Resources
I suggest adding "Sparse Resources" as another hard mission parameter that reduces ore spawning rates and plant edibles. The former can be replaced by rocks and the latter replaced by more bushes or just not even spawn. Based on my own game play, I would think ores could be reduced by 50% and edible plants reduced by 75-90%. The latter would make the farming skills more valuable. This should be stack-able with any of the other difficulty choices as well.