Here is the full list of all 27 Best Elf achievements.
Starting Prologue.
Starting Chapter One.
Afternoon Affection from Eleanna.
Afternoon Affection from Zariinna.
Starting Chapter Two.
Spent time with Durandall.
Unlock Eleanna's backstory.
Unlock Zariinna's backstory.
Recieve a little help from Zariinna.
Recieve a little help from Eleanna.
Visited by Durandall.
You found the Goblin Princess.
Released on the Goblin Princess.
Left the Goblin Princess Alone.
Starting Chapter Three.
Defeated the Sludge Monster!
Fail to Defeat the Sludge Monster.
Met the Mysterious Fox.
Defeated the Mysterious Fox.
Starting Chapter Four.
Rejected by Goblin Princess.
Clear Goblin Princess's route.
Clear Eleanna's route.
Clear Zariinna's route.
Clear Harem ending.
After Credits.
Unlock all CGs.