Full list of all 34 Monster Sanctuary achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
All achievements
Achievements they've won
Achievements they've not won
Donate 100 Monsters to the Monster Army
Complete twenty five battles in the Infinity Arena OR PvP
Obtain all monsters
Receive 5 star scores against all Champions
Uncover the whole map
Become a Keeper Master
Beat all of Trainer Gotthelm's challenges
Defeat Marduk
Explore the forbidden catacombs
Enter the Land of Blobs
Uncover the source of Marduk's powers
Recover long lost treasure
Deal over 10,000 damage in a single hit
Win 200 wild enounters
Achieve at least a 25 x Combo
Restore balance to the Sun Palace
Upgrade 50 pieces of gear
Defeat all monsters in a single turn
Defeat the Goblin King
Evolve a monster
Obtain a shifted monster
Receive a 5 star score in the Champion Challenge
Prove a worthy opponent
Become A Keeper Lancer
Confront the Alchemists in the Library
Pass the Oracle's test
Receive a reward from the Monster Army
Discover a hidden room entrance
Calm the Blue Caves
Receive a Tanuki Egg
Help out a resident of the Sanctuary
Complete Old Buran's training
Five-star a battle
Hatch first monster