At the main menu, press Up(2), Down(2), Left, Right, Left, Right, Up(2), Down(2), Left, Right, Left, Right to unlock all animals, foliage, buildings, and other objects. If you entered the code correctly, you will hear the sound of an elephant.
All animal housesChange a guest's name to "Andrew Binder" to unlock all animal houses.
All animal sheltersChange a guest's name to "John Wheeler" or "Adam Levesque" to unlock all animal shelters.
All animal toysChange a guest's name to "Lou Catanzaro" to unlock all animal toys.
All foliageChange a guest's name to "Charlie Peterson" to unlock all foliage.
All scenarios completedChange a guest's name to "Akiyama".
Money is donated to zooChange a guest's name to "Bill Gates".
Animals breed more frequentlyChange a guest's name to "Dr Dolittle".
Endangered animalsChange a guest's name to "Steve Serafino".
Sick guestsChange a guest's name to "Zeta Psi".
Blue shirtsChange a guest's name to "Mr. Blue".
Brown shirtsChange a guest's name to "Mr. Brown".
Orange shirtsChange a guest's name to "Mr. Orange".
Pink shirtsChange a guest's name to "Mr. Pink".
White shirtsChange a guest's name to "Mr. White".
Yellow shirtsChange a guest's name to "Mr. Blonde".
Bonus scenariosThere are four bonus scenarios that are unlocked by completing a scenario on different difficulty settings (beginner, advanced, etc.).
Control credits screenAt the credits screen, tap the lion at the bottom of the screen. It will put a piece of trash in the trash can. If you tap it again, it will take it out.