I am a HUGE huge fan of the Zoo Tycoon series. Zoo Tycoon 2 is well worth buying - the graphics are amazing and the gameplay is quite addictive!
First off, the premise. You are the owner of a zoo. Your aim is to create the best possible habitats for your animals so they are happy - and to keep your visitors happy so they give you money so you can get more animals. It is just as important to educate the people as it is to sell gifts to them. It is critical that you learn what environment each animal enjoys - from the type of terrain to the trees, foods and other such items that they want around them.
Where Zoo Tycoon made you do this all through memorization, Zoo Tycoon 2 has really optimized things. Right on your animal screen, you have a zookeeper telling you what that animal enjoys. So your selections are automatically limited to the appropriate items. It's very easy to paint terrains, add in foods, shelters, toys and more.
Moving terrain up and down and changing its type does not cost money, so there is no fear of "how much will it cost to fill in this lake". That makes general construction MUCH easier, and you save up your money for building the fences, shelters and various gift shops that keep your zoo running.
While some of these changes are very common sense and make the upkeep of your zoo much easier, some of the simplifications actually seem to make the game TOO easy. For example, in the first game, it mattered where you put the trees and rocks. Some animals liked having a 'full' landscape to hide in, while others liked having trees along the edge and a nice big open area to run in. With this current game, they really don't care. Drop in a tree and a rock and they're happy. It gives me much less of a sense that the animals even notice what I'm doing.
There are the normal challenges, and the sandbox mode, so you can either tackle a specific puzzle or just play in a zoo to your heart's content. The prompts are always quite humorous and entertaining. The message in the game is clear - saving animals is important, and having happy animals is important. They emphasize donation boxes heavily - perhaps trying to encourage us to donate when WE go visit zoos.
The graphics are just amazing, and you can zoom right in to each animal. There is a 'camera' mode where you can walk around in your zoo from a first person view, taking action photos of creatures and things. It's really quite fun! There are the traditional clipping issues - sometimes the zebras seem to merge into each other as they turn around - but that's a standard problem in pretty much any game involving polygons and motion. It makes for some amusing photos of two headed horses :)
Zoo Tycoon 2 Walkthrough
Buy Zoo Tycoon 2 from Amazon.com