Sonic Adventure
  
Dreamcast


Play as Super Sonic: 


  Beat the game with every character and the 7th character; "Super Sonic" will 
  be opened.
Play as Super Knuckles: 


  Beat the game with all six characters, then beat it again as Knuckles. Then 
  hold X + B at the character select screen. 
Play as Tails: 


  After he is obtained, use Controller 2 to play as Tails. 
Hidden artwork:


  Put the game disc in a PC CD-ROM drive to find additional art images from the 
  game. 
New Twinkle Park Race view: 


  Press Up on the Twinkle Park Race level to switch views. 
Full pause screen:


  Press Y + X at the pause screen.
Alternate Snowboards:


  Just before entering the snowboarding part of the game, press "X" 
  for a Blue Board, and "B" for a Yellow Board.
To Get a Metal Chao Baby:


  To get the metal Chao Baby go to the mystic ruin and go to the water fall, look 
  to your right and you'll see a platform, push it in and behind the water fall 
  a metal egg will come floating to land. Go to the nearest Chao garden and toss 
  the egg in and it will hatch! 
To Get a Gold Chao:


  Go to the shop in the first town where the guy tells you not to use the backdoor. 
  Go in the open area where you first fight Chaos and look in the corner with 
  the trees for a gray rock shaped like an egg. Take the rock to the shop and 
  set it down. Pick up the gold egg in the window and the exit will seal off with 
  bars. Take the gray rock and set it where the gold egg was and it reopens the 
  exit. Take your gold egg to the Chao garden and hatch it -- Gold Chao. 
To Get a Black Chao:


  Wait until Robotnik's ship crashes, then go to the prison (where Amy was being 
  held earlier). In one of the cells there should be a black egg. Pick it up and 
  walk out into the large corridor (the one with the cleaning robots and the trams) 
  and go to the very end. You should reach a teleporter pad. Step onto the pad 
  and you'll be transported to the third Chao Garden with a soon-to-hatch black 
  Chao. 
Growup Chao: 


  Grab 10 animals from a stage with robots & go to your chao at Station Square, 
  Mystic Gardens & Egg Carrier. Give your chao the animals & keep repeating. Note: 
  Do not hit your chao or it'll never grow into a good racing machine & your chao 
  will vanish & may appear again if you wait until it re-appears.
  
 Thanks to Revolution reader ArtiLiroy, Spencer Welch, Tomahawk Sam, RaVeN 
  2799, John Lawver, Jonny scully tyus, Axle 47, Mike Le, Sanschel Chris B, Brendan 
  "Computer Wiz" Backhaus and Kevin!