Type Horza as your nickname and press c you wiil get $50,000.
This can be done repeatedly.

Kristy

When you design a water ride, a race car track, or a roller coaster (big dipper, monorail, etc.), just place a few pipes and join them together, then add the entrance - this won't cost much, and afterwards you can just pull the ride to pieces (except the entrance), and you'll have a HEAPS long ride that won't cost you much at all!

mark jones

When you build a side show make the prize $400 then make the people pay $500, but you must put up the probability to about 80%, they are happy and you are always making profit even if they win.

Joseph Cantrell

For a megapark, type in "DEMO" as your nickname. Continue and you should get a megapark with almost all of the rides but a few problems for you to fix.

Marcus Bergfors

Type HORZA as your nickname and press: ctrl-z to get all the shops alt-z to get all the rides shift-z to get all the trees and toilets etc.