Thank you!! The hatching and the chicken sound, as well as the touching the ground sound are all recordings of me, hahaha!
As for full screen, I had trouble with Safari on macOS too. Not sure why. I need to investigate further.
Thank you Ioanni!! Yes, indeed. This is a super simple game I started extending. The original is based on the Building Games with DragonRuby book. I plan on extending it more, after I submit my KIFAAS entry 😃.