Here is the full list of all 60 Legend of Grimrock 2 achievements.
Find the Relic
Find all secrets
Complete the game with Ironman and Single-use Crystals modes turned on
Complete the game with old school mode
Polymorph 10 times
Dig up all treasure chests
Assemble the Meteor Hammer
Enter the Nexus
Enter the Shrine of Balance
Visit all levels
Complete the game with hard difficulty setting
Defeat the Lindworm
Max out three skills
Find 8 skulls
Enter the Castle
Collect four elemental essences
Collect and wear full set of Meteor armor (6 pieces)
Collect and wear archmage's uniform (4 pieces)
Collect and wear full set of Crystal armor (6 pieces)
Enter the Crystal Mines
Catch 25 fish
Defeat the Wormbound brothers
Mix a total of 50 potions
Mix a total of 10 potions
Find 50 secrets
Find Bane
Collect and wear rogue's wardrobe (5 pieces)
Open 5 gold locks
Defeat a Magma Golem
Learn 15 spells
Find the pie
Open the gate to the Cemetery
Enter the Pyramid of Umas
Dig up three treasure chests
Defeat a monster with a backstab attack
Defeat Herder's Den
Defeat the Summon Stones
Kill 250 monsters
Kill a monster with a single blow
Open the door to the Archives
Perform 500 missile or throwing weapon attacks
Perform 100 power attacks
Find 25 secrets
Cast 500 spells
Defeat the Ratling Boss
Travel 10000 tiles
Reach level 10 with a farmer
Summon the Viper Roots in under 6 minutes
Visit 10 levels
Max out a skill
Dive 250 tiles
Collect an elemental essence
Cast 250 Spells
Find 10 secrets
Perform 500 melee weapon attacks
Kill a monster by teleporting on it
Defeat the Viper Roots
Cast 25 spells
Kill a monster by throwing pants at it
Deal a killing blow with unarmed attack