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