I'm trying to complete the last scenario which requires me to get 5 star rated animals. What exactly makes an animal 5 star rated? I have a lot of animals with good genes that are 0 star animals, so is there anything else I should be looking for?
I’m not sure about scenario but in franchise high appeal animals will eventually become 5 star animals. Gorillas, lions, etc. I would try to adopt the highest appeal animal(s) you can and make sure they are happy (enrichment, social group, etc.) Add a few good viewing points (properly sized enclosure, elevated paths/bridges into the habitat, plants around view points, education speakers, etc. and you should be on your way.
I completed that mission earlier today and got the gold star. I had no idea about what makes an animal 5 star rated, hence I searched this forum earlier this week. There is however a brief section in the in-game help about star rating which I attach