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