Here is the full list of all 30 Dungeon Travelers: To Heart 2 in Another World achievements.
Reach the dungeon's 3rd floor.
Reach the dungeon's 2nd floor.
Obtain every achievement.
Unlock the Dark Cathedral.
See something traumatic.
See the true ending.
Defeat the four mighty wanderers.
Reach the dungeon's 11th floor.
Reach the dungeon's 12th floor.
Reach the dungeon's 13th floor.
Reach the dungeon's 14th floor.
Reach the dungeon's 15th floor.
Reach the dungeon's 16th floor.
Reach the dungeon's 17th floor.
Reach the dungeon's 18th floor.
Reach the dungeon's 19th floor.
Reach the dungeon's 20th floor.
Unlock the Nearby Forest.
Unlock the Battle District.
Unlock the Royal Tomb.
Unlock the Thirty-Tiered Tower.
Use every technique in the game.
Use every magic spell in the game.
Reach the dungeon's 4th floor.
Reach the dungeon's 5th floor.
Reach the dungeon's 6th floor.
Reach the dungeon's 7th floor.
Reach the dungeon's 8th floor.
Reach the dungeon's 9th floor.
Reach the dungeon's 10th floor.