Here is the full list of all 53 Beautiful Mystic Survivors achievements.
Defeat a final boss with Cassandra
Complete 6 secret shrine or cursed shrine challenges
Defeat level 2 final boss
Defeat 100,000 enemies
Complete 3 secret shrine or cursed shrine challenges
Evolve the Sword
Evolve Shield 3 times
Defeat level 1 final boss
Collect 4,000 gold during a single run
Defeat the first boss of level 1 3 times
Collect 2,000 gold during a single run
Complete secret shrine or cursed shrine challenge
Use special abilities 250 times
Defeat 20 elite enemies with the Scythe
Rescue Melisandre
Collect 5,000 gold in total
Pickup 30 healing potions
Reach level 60
Collect 1,000 gold during a single run
Defeat the first boss of level 1
Use special abilities 100 times
Survive 16 minutes with Rosaline
Pickup 100 items from the ground
Pickup 50 items from the ground
Obtain 3 legendary weapons
Use special abilities 50 times
Pickup 10 healing potions
Equip 6 passive items in a single run
Obtain a legendary weapon
Defeat level 2 final boss 2 times
Pickup 10 items from the ground
Rescue Ciara
Level up the Holy Pedant to level 4
Defeat the first boss of level 2
Survive 5 minutes with any character
Survive 16 minutes with Cassandra
Survive 16 minutes with Isaya
Equip 6 weapons in a single run
Defeat level 2 final boss 3 times
Defeat a final boss with Isaya
Defeat 400,000 enemies
Defeat 200,000 enemies
Walk 10,000 meters with the Fire Boots
Defeat a final boss with Ciara
Defeat a final boss with Rosaline
Craft 200 potions with Sophia
Win the first level with 3 different characters
Evolve the Bow
Survive 16 minutes with Ciara
Win 5 times
Rescue Minos
Beat level 3 with Minos
Kill 5000 enemies with Minos' active ability