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