Here is the full list of all 21 LOOPERS achievements.
Collect all trophies.
Complete the soundtrack.
Complete the gallery.
Complete the chapters.
Read up until “The Real Treasure.”
Read “Extra-Special Spell, Dinosaur Eraser.”
Read “What I Wished For, End of Eternity.”
Read “Confusion, A Botched Miracle.”
Read “Best of Friends, Time To Leave.”
Read “A Secret Wish, Final Fireworks.”
Read “Time Capsule, A Little Miracle.”
Read “Sleeping Beauty, History Repeating.”
Read “Mia's Request, Looper Rehab.”
Read “Treasure Hunt, Ferris Wheel Fireworks.”
Read “Living Large, Dying Inside.”
Read “Welcome to the Spiral, Welcome to the Loopers.”
Read “Lost Souls, Endless Loop.”
Read “Sagashi-Onna, Descent Into Madness.”
Read “Strange Girl, Stranger Events.”
Read “Old Friends, Late-Night Hunting.”
Read “Prologue.”