In order to play the actual last stage of Sonic Adventure 2, finish both Hero and Dark side story games. Once done, go into story mode and a "Last Stage?" menu selection should appear between Hero and Dark selections.

In order to unlock the Kart game, in the Hero Side story, complete Tails driving quest and in Dark Side story, successfully finish Rouge chase mission.

To unlock Boss Attack mode, complete either Hero or Dark side story modes. You'll be able to fight each boss from either Hero or Dark side.

To unlock the Chao Dark Garden, you must raise a Dark Chao with one of the three Dark characters. Continually feed and train your Dark Chao and it should evolve (creates a tear-shaped "cocoon"). Once it evolves, descending stairs should appear at the main Chao lobby leading to the Dark Garden.

To unlock the Chao Hero Garden, you must raise a Hero Chao with one of the three Hero characters. Continually feed and train your Hero Chao and it should evolve (creates a tear-shaped "cocoon"). Once it evolves, ascending stairs should appear at the main Chao lobby leading to the Hero Garden.

Everybody wants to play as Super Sonic, and now you can. All you need to do is complete "Last Stage?" in story mode, and you'll unlock both Super Sonic and Hyper Shadow.

To find the hidden artwork on the Sonic Adventure 2 disc, pop it into your PC's CD-ROM drive. Look at the CD's directory to find a number of wallpapers, including an endearing picture of a Chao.

To unlock a 3D version of the classic Green Hill stage (from Sonic the Hedgehog on Genesis), earn all 180 emblems. The new stage will appear on the world map.

If you play through the Chao Adventure 2, the VMU game, you will find seeds at the end of some of the quests. These seeds can be taken to the Chao garden and produce rare fruits. In order to plant these seeds, you need to first win the shovel and watering can in the beginner Chao races. As soon as you have won these, take the seed out of the VMU and give it to one of your Chao. The Chao will take it, plant it, do a little dance and a little weed you appear. Eventually, it will grow into a tree that you can use to help improve your Chao stats.

There are several places in SA2 that you can see Big the Cat from Sonic Adventure. Here are a few of them:

1. City Escape: About 3/4 of the way down when you're running away from the truck look on the right sidewalk to see him running away.

2. Radical Highway: After going in one of the rockets look at the blimp to the left and he will be sitting on it.

3. Pumpkin Hill: Go to the area where the train is stuck (it's going back and forth) and he is behind one of the gates waving to you.

4. Cannon's Core: With Rouge, go to the top of the highest pillar in the main room and look up. He's jumping up and down.

5. When you're battling against Shadow with Sonic in the Green Forest area there is a grate. Look down in the grate and you can see Big fishing.

Go and chat with her in the Casino as Sonic after you finish the Sky Chase.

You must achieve A ranks on all of the Eggman's Stage.

This requires at least two VMUs, sometimes more - one of which must be completely devoid of any Sonic Adventure 2 data.

Take your VMU that has all of your SA2 data on it, and copy the main game file and Chao data to another VMU (the second VMU has to be COMPLETELY blank or this will not work).

When you go to your Chao Garden, there will be 2 new eggs, and your Chao that was in the VMU will be on both VMUs note: this deletes all Chaos that are in the Garden when you do the trick, so make sure they aren't there; a good place to put them would be in a third VMU.