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