SONIC ADVENTURE 2: BATTLE UNLOCKABLES
Boss time attack mode
Finish either side story to see all the scenes from the side of the story that you chose or you can play the Bosses that you fought in a time attack mode. To get both the Hero and the Dark modes you have to finish both sides of the game.
Last stage
Finish both Hero and Dark side story modes. Begin the story mode to access the Last Stage option.
Extra Island level
To get an extra Island level, you must get all the Emblems, including Kart, Timed Boss, and the emblems for all A rating. Once you have them all, which should total 180, the island next to the Green Forest level will have the face of Sonic on it. The new level is a 3D version of the Green Hills Zone, from Sonic The Hedgehog. This level has no missions, is very simple, and has many varying routes.
Extra costumes
Get A ranks on every mission with the character you wish to get the costume for.
Extra Chao Karate mode
You either have to Finish Hard mode, or all three original modes (Beginner, Intermediate, and Hard). Doing this will unlock the fourth difficulty mode, Super. The Super mode is very hard if your Chao is not strong enough.
Chao race kart
Finish all of Tails' missions with A ranks.
Advanced Eggman race kart
Finish all Eggman's missions with A ranks.
Eggman Robot race kart
Finish all of Rouge's missions with A ranks.
Advanced Knuckles race kart
Finish all of Shadow's missions with A ranks.
Advanced Shadow race kart
Finish all of Shadow's mission with A ranks.
Advanced Sonic race kart
Finish all of Sonic's missions with A ranks.
Get Flame on top of choa's head
First go to the water stage with Knuckles. Then look around till you find a sea monster animal. Go to choa garden and give it to one of your choa Look at the top of it's head It should have a flame on in.
Wool hat
To unlock the wool hat, you need to have at least 100 emblems. The blue mask costs 10,000 rings, the red mask costs 8,000 rings.
Unlock Amy for Kart Race
Get Rank A on all the Sonic stages.
Get A Chaos Chao
First, select a chao that has reincarnated twice. To check this, take your chao to the doctor and it will say how many times it has transformed. Now, when that chao is a baby, feed it ONE of ALL 21 animals in the game. There are 3 types of chaos chao. Hero, Nuetral, and Devil. In my opinion best chaos in looks and skills are Nuetral being the best, then Devil, then hero. For neutral, raise with both, ect. Than wait about 3-4 hours.