Zoo Tycoon 2 cheat codes:
Hold [Shift]+[W]+[UP] for ultra fast sun.
Free trees and other stuff:
When you are in any zoo mode (campaign, challenge, and freeform) most
zoos should have already existing trees(and occasionally things like
flower beds, benches, etc.) at the start. All you have to do is left
click the item you want and move it to where you want it. This saves
money when you are on a tight budget and is really easy.
Run in Zoo Guest Mode and Photo Safari Mode: Since left-clicking the
mouse makes you walk in Zoo Guest and Photo Safari Mode, and so
does W or Up, you can walk twice as fast (aka run) by holding two of these.