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