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