This stage is your initial playthrough of all 3 books. Here you will get all of the miscellaneous combat trophies as well as well as the ones for the story while also trying to get as many chests and sculptures as possible. This game is a pretty linear chapter-by-chapter game where you will play through the chapters in an open area while being able to look for hidden chests. The story shouldn't take long, given you focus on it.

Initiate
Finish the tutorial.

That Sounds Right
Use Seismic Sense for the first time.

Healing Touch
Use Katara to heal your teammates for the first time.

On Your Guard
Block 20 projectiles with your shield.

Airlift!
Launch 20 enemies.

They Should Watch Their Step
Trap 20 enemies.

Fire and Family
Play with a friend (one player as Zuko and the other player as Iroh).

My Cabbages!!
Destroy the cabbage cart 10 times.

Trusty Boomerang
Defeat an enemy using Sokka's boomerang to deliver the final blow.

Scroll Call!
Buy a bending scroll.

Your Journey's End
Beat story mode.

Can't Touch Me!
Beat 3 bosses without getting hit.

Gangbuster Gatherer
Beat all Animal Races with more than 75% of coins collected.

Gotta Touch 'em All
Interact with twenty different objects in the world.

Bending Master
Learn the four bending arts with Aang.

The Gaang's All Here
Unlock every character.

Put Out the Fire
Defeat Admiral Zhao.

Fire and Lightning Fizzle
Defeat Zuko and Azula.

The Fire Lord Is Finished
Defeat Firelord Ozai.

This stage has you going through all the levels in freemode and finishing all the quests while getting the remaining chests and special items.

Statuesque
Find and build all the sculptures.

Later, Momo!
Win all "Beat Momo in a Race" challenges.

Investigation Bender
Find all secret rooms and treasure rooms.

Master Treasure Hunter
Open all chests.

Beat All Quests
Finish all side quests.

This stage has you doing the spirit trials, getting their rewards, and using them to unlock every character's skills and abilities. Spirit trials are short challenges that usually require you to play under a certain restriction or do something special. Most will not pose much of a challenge, but some can be really difficult. These trials are also how you will get the final scrolls and pai sho tiles you need.

You Call That a Challenge?!
Beat all the spirit trials.

Pumped Up Punishment
Defeat a boss with Aang when all perks and bending moves are maxed.

Positively Perky!
Unlock all character perks.

NOTE: DO THE SIDE QUESTS FIRST CUZ THEY SPAWNING A NEW CHEST WHICH IS THE COLLECTIBLE AND I INCLUDED IT IN MY LIST

chapter (1): - Bending challenge (2 chests) - Fire Navy wrecked ship (3 chests) - Zuko's ship (5 chests)

chapter (2) - Kyoshi village (6 chests) - Bending Challenge (2 chests)

chapter (3) - Senlin Village (8 chests) - Bending Challenge (2 chests)

chapter (4) - Fire Temple (8 chests) - Bending Challenge (2 chests)

chapter (5) - Fire Nation Entrance (5 chests) - Fire Nation Hallways (7 chests) - Frozen Forest Bending challenge (2 chests)

chapter (6) - Agna Streets Morning (5 chests)- Agna Streets at Night (7 chests) and Bending Challenge (2 chests)

NOTE CHANGE THE TIME AT THE BOTTOM RIGHT OF UMMI BRIDGE BLUE CIRCLE.

chapter (7) - Omashu Streets (2 chests) Bending challenge (2 chests) - Sewers (3 chests)

chapter (8) - Manor Garden (2 chests) Bending challenge (2 chests) - Manor Chambers (4 chests)

chapter (9) - Drill Rooms (7 chests)

chapter (10) - Ba Sing Se (4 chests) - Lake Laogai (1 chest) bending challenge (2chests) - Dai Li Base (5 chests)

!!!! NOTE !!! DON'T SAVE AT THE LAST ROOM AT THE TOP YOU WILL GET LOCKED I RECOMMEND DOING A BACKUP SAVE BEFORE STARTING THE CHAPTER.

chapter (11) - Royal palace (9 chests) Bending challenge (2 chests)

chapter (12) - Royal Chambre (2 chests) - Crystal Catacombs (6 chests) - Hall C bending Challenge (2 chests) - Hall B Bending Challenge (1 chest)

chapter (13) - Fire City (8 chests) - Bending challenge (2 chests)

chapter (14) - Fire Nation Captial (2 chests) - Fire Lord Bunker (3 chests) and One bending challenge (2 chests)

chapter (15) - Air Temple (6 chests) 5 in the map, one near the bending underground - Entrance Hall Bending challenge (1 chest) - Earth Chambre Bending Challenge (2 chests)

chapter (16) - Boiling courtyard (8 chests) - Bending challenge (2 chests)

chapter (17) - Strange Island (1 chest) - Bending challenge Island (2 chests) - Strange Island City (7 chests)

Chapter (18) - Fire Nation Ship Indoor (4 chests) Fire Nation Outdoor (5 chests)

Finish all side quests.

In every chapter, there are optional side quests you can do. You will get these quests by either interacting with an NPC with a purple question mark over their head, or by interacting with a locked door. Finding some quests can be a bit of an issue, but approaching every NPC in a level can help with starting them. Along with that, some quests can only be completed after others, so if you can't finish one, try to see if the other will help. Most quests are basic fetch quests wanting you to get an item or beat up some enemies.

Note: If struggling with quests, you can open the quest menu with Options and go down to any quest and hold Cross to bring up a compass, which will guide you to an objective.

Some of the more difficult quests are the ones that want you to memorize a sequence of a song or a code. These are hard because the game doesn't keep track for you, so you need to manually document the answer, and along with this, after interacting with them all once, your compass will no longer guide you to them.

Here are the Answeres for the little memory puzzles:

To use the pipes or the wheels, you have to trigger a side quest in order to use them or well that count.

Chapter 15: The Western Airtemple

Hint: use the Compass for the Signs if you can't find them.