Eider

Well I will defend myself by saying that I wasn't even trying to get into what influence homosexuality has over the species as a whole. I was trying to point out that "evolution" or even "protection of the species" isn't really a valid reason for discriminating against people.

It would be valid only if we as a society saw prolonging our species as our primary objective, which we don't. People are generally allowed to do all sorts of things that endanger our lives and hinder our ability to reproduce. Using "evolution" as a reason to discriminate against homosexuals wouldn't make a lot of sense without discriminating against everyone else who is endangering our species including a lot of sick and disabled people who we generally have a lot of sympathy for. So is the intent to further the species a good reason to discriminate against homosexuals? Only if you think extreme cherry-picking is reasonable...

Is your game trying to capture the breadth of these topics, or are you trying to focus more on sustainability? It certainly ties into both climatology and ecology, but those are two fields in their own right as well. Ecology has a lot of fundamental concepts that aren't hard to understand at a general level and could easily be adapted to a game. You could make a game where the player has to help species by managing different types of habitats and solve problems that affect them. You can make games based on food webs, trophic levels, succession, etc. These concepts can be simplified to where they won't be too difficult to learn but still have a lot of potential for learning in them, and is certainly relevant to environmental protection.