Here is the full list of all 40 Attack on Titan 2 - there are A.O.T.2 achievements.
Successfully completed a Sneak Attack.
Increased friendship rank.
Used a Buddy Action.
Achieved a Battle Rating of S in any episode.
Acquired all trophies.
Got selected as the top performer during training in Episode 1 of the Story Mode prologue.
Completed Story Mode Chapter 1.
Completed Story Mode Chapter 2.
Completed Story Mode Chapter 3.
Completed Story Mode Chapter 4.
Completed Story Mode Chapter 5.
Completed the final chapter in Story Mode.
Completed 25% or more of the Scout Missions.
Completed 50% or more of the Scout Missions.
Completed all Scout Missions.
Achieved a Battle Rating of S in all Story Mode episodes.
Completed your first Dire Elimination.
Completed all Story Mode Dire Eliminations.
Reached 25% Gallery completion.
Reached 50% Gallery completion.
Reached 100% Gallery completion.
Leveled the protagonist to max level.
Leveled one character to max rank.
Unlocked all characters.
Eliminated a Titan with the Hook Drive.
Saved 100 or more comrades.
Avoided 100 Titan attacks.
Eliminated a total of 1,000 enemies.
Got 2,000 total body part destructions.
Had over 100 allies join.
Had over 100 allies die.
Completed 100 Side Missions.
Built 100 bases in battle.
Leveled one character to max friendship.
Leveled all characters to max friendship.
Sent 50 gifts.
Used 1,000 Wings of Freedom.
Used more than 100,000 RegimC40ent Funds in total.
Maxed out all training.
Maxed out Titan Research Room level.