Here is the full list of all 86 Ato achievements.
Beat Ato on Bushido Difficulty
Beat the first 3 bosses on Hell Difficulty
Beat Ato on One Hit Difficulty Mode
Beat Ato without collecting Talismans, Coins, Runes nor extra Magic
Defeat The Leader without killing his servants
Defeated Warden without the vision upgrade
Beat Ato without collecting a Rune
Beat Ato without obtaining a dodge ability
Beat Ato in 2 Hours
Once obtained, Successfuly perform the counter ability on an enemy
Obtain all scrolls
Collect EVERYTHING
Destroy 50 wall crystals
Perform the legendary move on an enemy
Perform the just-frame legendary move
Cut 50 stalks of bamboo
Completed Fatal Arena
Defeated Champ
Defeated Blameless
Beat Ato on Accessible Difficulty
Beat Ato on Experienced Difficulty
Defeated Demon
Collect all runes
Defeated Leader
Collect all coins
Defeated Phantom Shin
Obtain all talismans
Defeated Samurai
Completed Throw Arena
Defeated Cross Blade
Defeated Archer
Max out your magic meter
Defeated Tiny Warrior
Defeated Tempest
Completed Armor Arena
Defeated Turtle
Collect a magic bar
Defeated Vagrant
Defeated Monk
Defeated Geisha
Defeated Warden
Defeated Deceiver
Defeated Father Statue
Defeated Yari
Defeated Child Statue
Completed Spin Arena
Defeated Daggerman
Defeated Sentinel
Defeated Shadow Jin
Defeated Ancient Warrior
Defeated Mother Statue
Defeated Berserker
Equip a Rune
Obtain your first Rune
Defeated Twins
Hit opponent 5 times while they are launched
Jump 1000 Times
Defeated Bandit
Warp from one gate to another
Destroy a blue crystal block
Defeated Acolyte
Defeated Ninja
Defeated Guardian
Defeated Jin
Parry your opponent
Increase your max health
Obtain your first Coin
Obtain your first Talisman
Defeated Rogue