Regarding the question as to how to unlock scenarios (ZT1, I hope!), I have the following info, along with several other little fun items that you should enjoy, if you don't have these already:
NAME CHEATS
- Name a guest Adam Levesque and unlock all Animal Care research programs.
- Name a guest Lou Catanzaro and unlock all Animal Enrichment research programs.
- Name a guest Charlie Peterson and unlock all exhibit foliage.
- Name a guest Akiyama and unlock all the scenarios that ship with the game.
- Name a guest Steve Serafino and unlock all Endangered Animals research programs.
- Name a guest John Wheeler and unlock all animal shelters.
- Name a guest Ron Propst and unlock the Dinosaur Foliage research program. (DD)
- Name a guest Hank Howie and unlock all Staff Education research programs.
- Name a guest Eggman and dinosaur eggs hatch more quickly. (DD)
- Name a guest Dinoman and unlock all dinosaurs. (DD)
- Name a male maintenance worker Bob V and all currently broken fences are fixed.
- Name a scientist Dr. Scholl and all scientists walk twice as fast. (DD)
- Name an exhibit Cretaceous Corral and unlock theTriceratops.
- Name an exhibit Xanadu and unlock the Unicorn.
- Name an exhibit Super Croc and unlock Deinosuchus. (DD)
- Press $ (Shift+4) and get $10,000, but a random exhibit fence weakens (great time for the Bob V cheat!).
- Name a male maintenance worker George W and all the foliage in your zoo will vanish, but you'll receive $300 tax rebate.
- Name a guest Mr. Brown, Mr. Pink, Mr. White, Mr. Blue, Mr. Blond, or Mr. Orange and all guests and buildings currently in the zoo change to the associated color.
- Name male maintenance worker The Rock, all buildings are turned to rubble.
- Name a grizzly bear Deer and the bear will immediately break out of its exhibit (unless the fence is electrified).
- Name a guest Zeta Psi and all adult male guests in your zoo change colors and become sick.
- Name a guest Alfred H and a flock of birds appears to frighten your guests.
- Name a scientist Dr. Frankenstein and there's a 10% chance an egg will change its contents when the scientist visits. (DD)
- Name an exhibit Copralite Corner, all dinosaur poo turns into rocks. (DD)
- Name a guest Stinky and the guest causes other guests to be sick. (MM)
- Name a male guest rpro and female guests will run from him. (MM)
- Name a male guest Boogyman and the guest causes children to run away screaming. (MM)
- Name an exhibit Wonderland and get a bonus toward the chance of guests entering the zoo.
- Name a reindeer comet and all dinosaurs and dino eggs disappear from your zoo!
- Name an exhibit Microsoft and get double the normal donations at exhibits.
- Name a female tour guide Rosalie and all your tour guides will work for free.
- Name a female Zookeeper Susan Kittleson and Zoo Marketing effect is doubled (non-cumulative) (DD)
- Name a male Zookeeper Chuck Frizelle and Zoo Marketing effect is doubled (non-cumulative) (DD)
- Name a guest Russell C and all exhibit fences will become broken, letting the animals free.
EASTER EGGS
- On September 15 on the in-game calendar, a biplane with the Microsoft logo flies across the map pulling a banner with the Blue Fang logo.
- On their own turf, penguins are capable of killing pretty much any animal in the zoo.
- Guests entering the zoo on January 1 (New Year's Day) on the in-game calendar may be sick.
- October is Dinosaur Month! Purchase all dinosaurs at half price during the in-game month of October.
- On October 31 on the real-world calendar, all guests and buildings wear orange and black in honor of Halloween, a jack-o-lantern is available from the buildings and items menu, and a wicked witch flies over the zoo on a broomstick.
- On October 31 (Halloween) on the in-game calendar a witch flies over the zoo on a broomstick and a jack-o-lantern is available from the buildings and items panel.
- On Christmas (December 25) on the in-game calendar, Santa Claus flies over the zoo in his sleigh.
- Place a Mermaid Statue in an exhibit or show tank and it changes into a real mermaid. The Mermaid will not appear in the adopt an animal menu; however, you can continue dropping Mermaid Statues into water tanks to "adopt" more.
- Place a lion, a Bengal tiger, and a bear in an empty exhibit and unlock golden brick walkways.
- When penguins reach a happiness rating of 90+, they will do a happy dance.
- When lowland gorillas reach a happiness of 90+, they will do a happy dance.
- Earn the Excellence in Arctic Exhibit Construction and unlock the Iceberg. (MM)
- Earn the Best Sea Lion Show in the Country and unlock the California Sea Lion Statue (MM)
- Earn the Best Orca Show in the Country and unlock the Orca Statue (MM)
- Earn the Zoo of the Year award and unlock the Elephant Seal Statue. (MM)
- Earn the Best Dolphin Show in the Country and unlock the Bottlenose Dolphin Statue (MM)
- Win the Aquatic Show Park scenario and unlock the Show Grandstand 2 (MM)
- Win the Shark World scenario and unlock the Photo Booth. (MM)
- Win the Super Zoo scenario and unlock the Trio Statue. (MM)
Hope this helps!