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