I did everything in this project except the aggressive animals cannot be fed. There are 6 different animals and they all have their own speed. The "feedable" animals also have their own satiety value. Unlike the previous bonus feature, the Hard task is also somewhat easy but the Expert one is quite difficult. From simple math and display the output in the console to learning UI on your own, the difficulty curve from Hard to Expert is steep.

Quite the challenge on the last one yet it was worth it.