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