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