See the code on GitHub.
Hippo Game mentioned at ElixirConf EU 2019.
More about this game on my blog (Czech language).
Play the game online: The Elegant Monstrous Planthopper.
“Hippopotamuses have been the subjects of various African folktales. According to a San story; when the Creator assigned each animal its place in nature, the hippos wanted to live in the water, but were refused out of fear that they might eat all the fish. After begging and pleading, the hippos were finally allowed to live in the water on the conditions that they would eat grass instead of fish and would fling their dung so that it can be inspected for fish bones.” (“Hippopotamus” in Wikipedia)