Attack as any enemies as possible to get advanced moves quicker. Don't take on swarms of them though, especially Firebenders.
Increase attak damage:
Katara-Wear items with Life.
(Perhaps water or Lifebinder themed items)
Aang-Wear Agility items.
(Four Winds armor and trinkets work best.)
Haru- wear items containing Focus.
(Core items are a big help)
Sokka-Wear Strength items.
(He's definetly a "Soul Iron" kind of guy)
Note: The above are just suggestionz. Wearing all items of a set(Lemur, Badger, Bear, Unagi, Rain etc.) gives and extra boost.
Beat the Bear Boss- Chapter 3
Dodge its charges (brown dust behind it). When it glows red hit it with Haru's basic distance attack. It will stand on hind legs. Keep hitting till it comes down. Repeat to defeat.
Character Story Board Gallery
Collect all Set Items through level 6.
Cheat mode
Select the Code Entry option at the Extras menu, then enter one of the following codes to activate the corresponding cheat function:
Infinite health
Enter 94677 as a code.
Infinite stealth
Enter 53467 as a code.
Infinite copper
Enter 23637 as a code.
Infinite Chi
Enter 24463 as a code.
Double damage
Enter 34743 as a code.
One-hit dishonor
Enter 54641 as a code.
All treasure maps
Enter 37437 as a code.
Character concept gallery
Enter 97831 as a code.
Defeating the Maker's last machine
You can wait for it to stop attacking, or you can attack it, which will barely affect it. Once it is done attacking, you must attack the sides which turn red.
Defeating the prison guard
At first he will shoot fire balls at you. Keep moving left and right, and closer to him. Once you get close enough he will stop and try to hit you with his stick. Take a few steps back and let him try to hit you. Move, and when he stops, hit him. Do this repeatedly until he eventually kneels down. Then, hit him as many times as possible. He will not fight back. When he gets up, repeat the same process until there is a short intermission sequence. He will then use attacks such as curling up in a ball and swinging his bat in a figure eight style on both sides. Wait until he is done and then hit him. Repeat this until he is defeated.
Destroying the fire machine
This is the machine you must fight in order to find Katara. Dodge the fire bending. Try running left to right, then right to left. Continue this until you see a flashing light near it. This is your chance to attack. Hit it with Aang. You may use a Chi attack but just a plain attack should work just as well, however it takes time. You will have Saka (Katara's brother) fighting with you to do double damage. After about a quarter way down on HP, the machine will start throwing fire around. Keep a safe distance from this attack. It causes no real threat to your or your partner as long as you stay as far away as possible.
Easy experience
Whenever you are in battle you can go back later to get more experience.
Level Art Gallery
Collect all Set Items through level 3.
Story Board Gallery
Collect all Set Items through level 5.
Unlocking Moves-Caution!
If you want to unlock every single bending move, you must attack more enemies than normal. The first time I beat the game, I only unlocked Katara's Mass Freeze, Aang's Air Dome, and Haru's Quicksand! OK, maybe I did get a little far. But still, I didn't unlock everthing.