Animal Crossing: Wild World features a very minimal plot. The objective of the game is to pay off a debt to Tom Nook, who allows the player to move into a house he owns. If the mortgage is paid off, the player's house will expand until upstairs, left, right, center and back rooms are included. This is slightly different to the Nintendo Gamecube version, in which the finished house only consisted of a basement, a main room and an attic. While paying off a debt, the player can do a variety of optional tasks, including interacting with other villagers and filling the catalog of the things you have, like furniture, fish, clothes and stationary.

Animal Crossing: Wild World makes use of several of the Nintendo DS' features, including the touch screen, dual screens and internal clock. The touch screen is used for menu navigation and interacting with the surrounding area, including movement, using tools, talking to other villagers, entering buildings, picking up items etc. The dual screens are used to display the overworld on the touch screen and the sky on the top screen, which varies depending on the circumstances.

Secrets

Find out tomorrow's weather
If you have a TV, make sure you pay attention when the weather show is on. It'll tell you, in pictures, how the weather will be the next day. It'll either show a picture with the sun for a clear day, or clouds with snowflakes for snow, or rain etc. This is important if you want to catch a Coelacanth.

First Roof Color
Your first house's roof color can be customized, believe it or not. Simply change your DS's menu color from the DS setup screen and your house will have that same roof color. NOTE: this only works with the color you have set when you first move into a house.

Free bug net
While the bug contest is going on, talk to Tortimer and and he will give you a free bug net. This only works if you don't have a bug net on you already.

Free Fishing Rod from Tortimer
If you go up and talk to Tortimer at the Fishing Tourney and you don't have a fishing rod with you, he should give you his. It's just a normal fishing rod, but hey, it's free.

Free Pack of Flowers
Talk to Tortimer during the Flower Fest for a free pack of flowers!

Getting furniture from your neighbor's houses
If an animal in your town has furniture in his or her house that you want, send them seashells, unwanted furniture, or fossils to them in the mail. They'll usually put these gifts in their house, displacing whatever was there before. Check the recycle bin at your Town Hall and the item you wanted from their house may be in there.

Hold 10 extra items
This is a really easy trick. Just buy 10 letters, leave them blank, then pull an item onto it so that it becomes a present.

How to change the background of your inventory.
Grab a shirt or pattern. Drag it to the lower left corner. It'll be over an invisible space, drop it.

Instantly Cure Sick Villagers
When one of your villagers is sick, you'll have to give him/her some Medicine every day for about a week to cure him/her, but an easier way to cure him/her is to get on WiFi or multiplayer, then the villager will be immediately cured when someone visits your town.

Make animals stay in their houses
To make animals stay in their houses, simply go to the gate and ask Copper to open the gates for DS to DS visitors. After the gates are open, your animals will stay in their houses. This makes deliveries VERY easy if you are having trouble finding certain animals, or if you are trying to look at a certain animal's house and they don't stay inside much.

Store more items
Speak to Pelly in the town hall (or Phyllis, if it's at night) and choose "Save a Letter". You can save up to 75 letters and you can attach gifts/items to these letters so you can keep 75 items in the post office, plus the 90 items in the dressers and you can do this with all 4 characters, for maximum item storage.

Here's some Action Replay fun in this popular title: