Here is the full list of all 44 Apocalypse Party achievements.
Unlock all characters
Hold 4 firearms simultaneously
Unlock all Weapon Archives
Own 6 dragons simultaneously
Complete Male Plus Male
Have a child
Have the talent 【Mighty Loner】 and clear the game
Unlock the encrypted code
Defeat the boss Horseman of War·Furnace 3 times
Defeat the boss Horseman of Famine·Huhu & Lulu & Dodo 3 times
Defeat the boss Sixth Seal·Eclipse & New Moon 3 times
Unlock all Sacred Ability Archives
Unlock all Talent Archives
Defeat the boss Dwarf King·Evil Eye 3 times
Defeat the boss Deer-headed Elf·Raging Wind 3 times
Defeat the boss Horseman of Plague·Loving Father 3 times
Clear 【Chapter 3: Nightmare】
Clear 【Chapter 2: Heroes】
Clear 【Chapter 1: The Messiah】
Defeat the boss Death Knight·Headless 3 times
Clear 【Prologue: The Trial】
Defeat the boss Ancient Titan·Tiny 3 times
Complete a multiplayer game
Play one game
Defeat Satan in the Prologue
Win the game as a zombie
Unlock all character skills