Press green flag once. That is all you do. Listen and enjoy. I've updated it so that if you click on a minion/animal, it makes that sound it would make. I can't get the zombie for some reason.
Reference to my favourite game - Necromerger I love this. I tried so many things but I finally got the sound to work. Its been put in my studio - 18's Studio. Updated - Skeleton, Zombie, Eye monster, Spider, Mummy and Werewolf.