When you have a saved game file from 'Avatar: The Last Airbender' on your memory card the 3rd Appa Flight Mission will become an available option.

Try entering these codes at the 'Password' screen which is on the 'Main' menu if you need help progressing in the game. Click the left arrow and then 'Cheat Entry' to enter the code and enable the effect you want.

Unlock Max Level:
Enter the code 89121

Unlock ALL Bonus Games:
Enter the code 99801

Unlock ALL Gallery Items:
Enter the code 85061

Unlock Double Damage:
Enter the code 90210

Unlock One-Hit Dishonor:
Enter the code 28260

Unlock Infinite Life:
Enter the code 65049

Unlock Infinite Special Attacks:
Enter the code 66206