Here is the full list of all 39 Death end re;Quest 2 achievements.
Completed all story endings and explored all paths.
Viewed the EX Ending.
Viewed the Fallen Ending.
Defeated 1000 enemies.
Learned 15 of Lily's skills.
Played the Ao Oni mini-game.
Defeated Ao Oni in the Pain Area.
Learned 15 of Clea's skills.
Used Glitch Mode a great many times.
Learned 15 of Al's skills.
Viewed all of the Death Ends.
Viewed most of the main story.
Viewed the True Ending.
Cleared Chapter 10.
Defeated the final boss.
Viewed many story events.
Cleared Chapter 9.
Cleared Chapter 8.
Learned 15 of Celica's skills.
Learned 15 of Shina's skills.
Learned 15 of Lucil's skills.
Cleared Chapter 7.
Used Glitch Mode a handful of times.
Cleared Chapter 6.
Learned 15 of Liliana's skills.
Cleared Chapter 5.
Cleared Chapter 4.
Cleared Chapter 3.
Learned 15 of Rottie's skills.
Learned 15 of Mai's skills.
Used a Flash Drive skill for the first time.
Cleared Chapter 2.
Viewed most of the sub-events with your classmates.
Activated Super Knockback for the first time and sent the enemy flying.
Entered Glitch Mode for the first time.
Activated Knock Blow for the first time.
Cleared Chapter 1.
Entered Camp for the first time.
Activated Knockback for the first time and sent an enemy back.