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