Tiny Chao Garden
For the first time, you can now connect two different format software! Now connect "Sonic Adventure 2 Battle" for GameCube with the software for Game Boy Advance, "Sonic Advance."
You can even transfer your Chao to your Game Boy Advance even if you don't have the software, Sonic Advance. From now on, you can take your Chao anywhere you want at anytime. There is a downloadable movie that shows you how to use the link.

The tiny chao garden can be accessed through the Game Boy Advance, with or with out Sonic Advance 1, or 2. (Note: If using the Tiny Chao Garden without Sonic Advanced 1 or 2 connected you will only get to use a copy of your chao in the Tiny Chao Garden and you will be unable to save anything.
Games

Clicking on one of these Game Boy Advanced icons in the Tiny Chao Garden will take you to a game where you can earn rings to buy items for your chao (Note: If you turn off the power on your Game Boy Advanced you will lose all your rings)
Rings

Rings can be earned in the mini games you can use them to buy fruits.
Items
You can buy items in the Tiny Chao Garden that can't be bought anywhere else.