Here is the full list of all 23 Dungeon and Gravestone achievements.
Reached 10F
Defeated 20F boss
Defeated 40F boss
Defeated 60F boss
Defeated 80F boss
Defeated 100F boss
Reached 150F
Found Shadow Town
Conquer the Slime Cave
Defeated 100 monsters
Levelled up 1000 times
Returned alive 100 times
Died 100 times
Caught all kinds of fish
Ate all kinds of food
Learned all kinds of magic
Completed 100 quests
Released 30 skills
Completed Monster Library
Saw First Ending
Saw True Ending
Saw Mysterious Ending
Saw Shadow Ending