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