Emblems

• You can earn 180 Emblems in "Sonic Adventure 2 Battle," and collecting them all unlocks a secret stage called Green Hill Zone. Instead of being distinguishable by type, their only difference is in what players need to do to gain them.
  
  Players can earn Emblems in the following ways:
  
  3 by completing all of Boss Attack mode.
  3 by completing all of Kart Race mode.
  3 by completing the game with every story mode: Hero, Dark and Final.
  4 by completing Chao Karate mode.
  5 by completing Chao Race mode.
  7 by completing every mission objective in every stage to achieve "A" ranking.
  155 by completing every mission in the game.
  
  

Black Market Eggs

• In the game's Black Market, players can spend their accumulated rings to buy Eggs in different colors. The different colors signify what color the Chao will be when it hatches. Players can mate different colored Chao to create specific breeds.
  
  Eggs come in the following colors: White, Blue, Red, Yellow, Orange, Sky Blue, Pink, Purple, Brown, Green, Gray, Lime Green and Black.
  
  

Black Market Shiny Eggs

• Players can also buy Shiny Eggs from the Black Market in shiny variations of the regular Egg colors. Players can also combine the ensuing Chaos from these Eggs to produce even more variations when they mate.
  
  The Shiny Eggs come in shiny versions of the colors above.
  
  

Tiny Chao Garden Item Shop Eggs

• While playing "Sonic Adventure 2 Battle," players can use a Game Boy Advance to GameCube Link Cable to connect to the Game Boy Advance game "Sonic Advance." By doing this, they can access the Tiny Chao Garden, where they can raise their Chao one by one. This garden has its own item shop where players can buy Egg types in colors they can't get in the main game, allowing for even more mating combinations.
  
  The Tiny Garden Eggs are in colors as follows: Normal, Silver, Gold, Ruby, Sapphire, Amethyst, Emerald, Garnet, Aquamarine, Peridot, Topaz and Onyx.