Dellfire

Because the game takes place in a post apocalyptic world their should be some evil raiders or bad guys that appear that try to steal natural resoueces kinda like pests and has the hidden message about healthy enviroments and recycling. Maybe you can grow plant towers or plant something to scare them off. Because these things would be natural they would good for the environment and your creature. This would not be violent just a small challenege to keep in mind.