Chao Garden

A good reason to replay the game. You take of these critters and have them compete in different mini-games which vary depending on what platform you're playing on. The NGC (and subsequent platform releases) have the Chao Karate minigame while the Dreamcast original has the Chao-Racing minigame. There are also minor changes like a stat-screen appearing when feeding the chao in the NGC (and subsequent versions) and the introduction of a Black Market. One levels up one's Chao by feeding them animals or Chaos drives. There are many different Chao breeds and 3 Chao gardens