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.

Animal Crossing: Wild World makes use of several of 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.

HINTS

CHARACTERS

Crazy Redd: Detecting forged items
Pay attention to Redd's body language. If a yellow star shaped object appears on his eye, then most likely the item is forged. 

Dr. Shrunk
When Dr. Shrunk enters your town for the first time, he will ask you how your emotions are going. Say "I'm in a slump". He will give you a list of emotions to learn. Choose one of them and he will teach you how to express that emotion. After that, if you have a friend over and want to express your new emotion, it will be the little bunny pictures directly under the speech bubble.

Gracie
Occasionally, you will get a bonus item on the certificate from Gracie. It will be the rarest shirt - the Moldy Shirt. Do not sell it to Tom Nook because you cannot re-order it from your catalog.

Gulliver: Appearance times
Gulliver always flies above your town at 32 minutes past the hour, at any hour.

Harriet: More haircuts
Get a haircut from Harriet on consecutive days until you have had all six of them. The next day, get another haircut from her and he will offer the haircut styles for the gender opposite that of your character.

Here's a video of this popular game: