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