How to I build new items in each area?

To build new items in each area, you will need to collect a certain number of specific animals in the game as well as Gems.
To collect different animals in the game, you will need to destroy as many Badniks as possible in each race that you take part in.
To find out how many animals you need for each section, you will need to click on the build icon which is located on the bottom right-hand side of the screen. Once selected you will see individual icons with an animal icon and the amount you need to unlock it.