It's a simple yet addictive game and the DS is a natural platform for this game.
Graphically this game looks exactly like the original Animal crossing with it's toony and light hearted style. While it's not the best graphics you're going to see on the DS, it's fine for this game.
The sound is the same as the original, nice light hearted music and the funny "Animalese" voice work. You do have the option to change this to the standard sounds you hear when text is displayed if you find it annoying however.
The gameplay is great, there are tons of things to do, lots of customization options, and nice expansion potential. Plus with WiFi for this game it adds a new level to the Animal Crossing franchise. Plus the games controls are wonderful (they might take a little getting used to however for some) because you can play the entire game with the stylus or with the control pad and buttons.
While it's not the meat of the game, WiFi is one of the things that really makes Animal Crossing shine. Not only do you visit others towns, but there are lots of things that can happen when you do. Neighbors will move in and out of your town to and from others, you'll exchange constelations in the sky, clothing patterns, and more. You can also go into tag mode (put your DS in a passive mode where it basically sits idle waiting for other DS's in the same state to enter range) and when someone else in tag mode passes by you'll exchange messages in bottles and events can even happen at that point (i.e. people moving from one town to another).
The only thing I can say that I don't like abou the game is that there could have been slightly better use of the controls in some aspects. For instance, at times a ballon with a package will fly across the sky and you have to get yoru slingshot out to hit it. At times this is very cumbersome becausee you have to open the menu, drag (or button select it) it onto your character, then close the menu, and hope it's not gone by the time you get there. There could have been some hotkey setups for tools since many of hte buttons do the same function (i.e. the shoulder buttons pretty much just sever to let you run, as well as one of the regular buttons). The shoulder buttons could have been use to cycle through your tools for instance.
All in all this game is well worth playing if you have a DS and is great reason to buy one if you've been thinking about it. AC:WW is also a great game to play with friends or as a couple if you've been looking to share a gaming experience. There is abundant replay value and lots of fun to be had.