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