Extra features that I added (other than what was given):  

1. You can change the Ground's material by pressing numbers 1 2 3 4 on your keyboard  

2. You can change the food you feed to the animals - pizza / steak / banana using numbers 5 / 6 / 7 

Challenges that were there for us to do:  

4. Score increment, life decrement and game over log messages   

I have uploaded the c# scripts I used for this game in the github repository. Feel free to check them out or use them as a reference.  

https://github.com/aatndev/Prototype2_Scripts