Here is the full list of all 42 UNSIGHTED achievements.
Defeat the secret final boss.
Defeat the Corrupted Tomb Guardian.
Defeat M.
Obtain a second Permanent Syringe
Skip on the water with the Spinner 5 times in a row
Win the encounter against two Shadow Creatures during the Prologue
Complete the game.
Beat the Blazing Automaton
Beat the Mechanical Eagle
Rescue one of the missing dogs
Beat the Frost Automaton
Beat the Arthropod King
Get 4 hearts of relationship with an NPC
Give Meteor Dust to someone
Beat the Ancient Guardian
Defeat 5 enemies by throwing them down holes
Beat the Forgotten Deity
Beat the Arachnid Queen
Defeat a Shadow Creature with normal weapons
Craft an item
Pet a puppy 5 times
Get 5 hearts of relationship with a dog
Get 20 perfect catches with the magnetic rod
Dig up 20 buried items with the shovel
Find all the Treasures from the Treasure Album
Complete the game on the Robot Apocalypse Difficulty, on New Game, or New Game Extra
Complete the game with 3 chip slots, no weapon upgrade, and max. of 1 Permanent Syringe. (buying weapons is ok!)
Complete the game in under 1 hour
Complete the game without rescuing Iris
Beat Anima Nightmare and Anima Essence without getting hit
Finish the Main Story without having a Corrupted Weapon in your inventory.
Complete the map 100%
Get all the Item Chests
Defeat the Factory boss first and the Garden boss last
Find the Jump Boots during the Prologue
Get a Meteor Shard during the Prologue
Perfect guard 30 enemy attacks without getting hit
Complete the Dungeon Raid with 0 deaths
Complete the Dungeon Raid in less than 20 minutes
Complete the Boss Rush with 0 deaths
Complete the Boss Rush in less than 10 minutes
Get 100 perfect parries in the parry challenge