Pros: 1) Scenarios are challenging 2) Easy to control 3) Bargain @ $20
Cons: 1) Too easy once you get the point of the game 2) Sound
The bottom line: Zoo Tycoon offers hours of challenging sim style gameplay. Do not miss this overlooked DS release!
The game is basically a direct port of the PC version. I was amazed at how easy it was to place the pieces and amount of statistics about the park that is available. My review is not intended to be a discussion of how to play the game, part of the fun is learning how to play from the in-game tutorials. Instead I focused on the high and low spots of my gameplay experience. A major plus is that you will find that little need for the manual. The only neglected part of the game was the graphics and sound!

History
Zoo Tycoon is almost identical to the PC version released by Microsoft in 2001. The goal is to run a zoo as a business and turn a profit. A second version, Zoo Tycoon 2, was released in 2004. Several expansion packs are available for each version of the series as well.

Several fan sites exist for the Zoo Tycoon series: http://z7.invisionfree.com/ZooMania/
http://www.zootekphoenix.com/forums/index.php
The odd part is that no official forum topics discuss the DS release.
The offical Zoo Tycoon Gamesite is:
http://thq.com/games/gameinfo.php?id=1216&upc=36105

Gameplay
The game has two playing modes: Freeform and Scenario. Scenario mode should be played first to go through the tutorial games and learn the ropes. Freeform mode features several map sizes and can become quite complex because you will need to design a good layout to maximize profits.

The game was designed with the stylus needed to control the in game menus. Since the game does offer a lot of control and options to configure, using the stylus for the menus speed up gameplay. Expect at least an hour to get used to the interface and in game library. The library is critical to learning how to construct exhibits for each animal type.

When I first started playing this game the game saves would become corrupted, causing me to lose all my work. After reading about a similar problem with Age Of Empires DS, the solution is to make sure the name you enter in your DS is longer than three characters. The saving feature has another problem though, only one save is available in the game. As a result, you cannot play the scenarios and have a freeform game on the side. The solution is to simply complete the scenarios without saving, but this means you have to make no mistakes.

Graphics/Sound
The heart of the game, the graphical layout of the menus, is near perfect in my opinion. I can easily see the characters on my DS and navigate the menus. You can even highlight an object and see it's statistics popup on the bottom screen. The graphics never slowed down while playing the game either. For example, I create a massive freeform game with 20 exhibits and could move my object selector (cursor) around the map with no problem. My only criticisms are of the cursor and the rectangle used to mark a selected square. The developers should have made the square brighter and easier to see. Another problem was that you could not zoom with the in game camera.

The sound effects in the game were annoying to me. If you are not in an exhibit, you will most likely hear the guests. Their sound effect is a short three second sound byte of a crowd of peole talking. Play this game with the sound off.

Extras
The game offers a card collection feature. The cards feature a picture and description of some of the animals in the game. You must complete scenarios to earn more cards.

Tips
You can find several ways to make money in the game beyond, the traditional admission price. Adjusting the admission price to can adversely affect attendance, which will also cause concession sales to drop. The quicker way to make more income is the animals themselves. Placing a single male and numerous females in an exhibit will encourage breeding. How this happens is best left to the Discovery Channel. Seriously, every month check the last animals in the Animal List. Some animals will appear out of order and have a higher ID than any other animal of the species. This is obviously a newborn. Sell the animal by clicking the $ icon on the right of the menu to sell this animal for quick cash. A large zoo can expect at least six newborns a month. I place several Bison cages in Freeform map mode to make the $1200 for newborns. Bison require little attention and the scenery they like is available from the start.

Summary
Everyone has at one time wanted to work in a zoo. A bunch of fuzzy characters and well documented features made running my own zoo easy. Fun for the first forty hours, Zoo Tycoon DS demonstrates that complex games can easily be written for the DS. The scenarios are the heart of the game, providing a lot of strategy in the placement of exhibits to get the most rewards. Placing animals and creating attractions for guests is only fun for a short while though. After completing all the scenarios, you will discover that the game is actually quite easy and the desire to maintain a thriving, self sustaining, theme park is almost boring. Poor camera control and neglected sound effects also play into my mixed opinion of this game. I have great hope that the future Sim City DS release will be as easy to play as Zoo Tycoon.