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