Press the buttons while in the game, either paused or resumed.

Code	Effect
Shift + Alt + I	All visitors die
Shift + Alt + O	Complete Scenario
Shift + Alt + L	Fail Scenario
Shift + Alt + C	Gain $100,000
Shift + Alt + N	Unlock all animals
Shift + Alt + W	Unlock all Scenarios
Shift + Alt + R	Unlock Everything