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