Here is the full list of all 79 Scarlet Tower achievements.
Survive 1 full day in Endless Mode
Slain World Eater on Corruption 10 Nightpine Valley.
Beat Corruption 9 before 22 minutes.
Create 10 different weapon fusions.
Collect 100 pieces of food
Defeat Krampus
Slain Octopus on the Ocean.
Slain Angler Fish on Ocean.
Help the Engineer
Buy the 12 different flasks from the secret seller.
Buy 30 flasks from the secret vendor.
Slain Flesh Demon on Plagulands.
Defeat 1000 Brains in the Plaguelands
Defeat 800 Snowman
Defeat more than 100,000 enemies
Defeat Puker 5x at Night Time.
Complete the Necromancer Quest
Complete the Templar Quest
Defeat 500 Tentacles
Upgrade Glacial Staff to Rank V
Defeat Death at Corruption Level 1 or higher
Defeat 500 Slimes
Survive for 24 minutes.
Survive for 24 minutes at Woods of Havoc.
Search for the lost egg in the world.
Upgrade Frost Staff to Rank V
Complete the Alchemist Mission
Complete the Elementalist Quest
Complete the Priest Quest
Defeat 5.000 Enemies at Night Time.
Upgrade Holy Bible to Rank V.
Find someone lost in the woods at nighttime.
Defeat 1000 Ghost Witches
Defeat Puker at Night Time
Complete the Paladin Quest
Upgrade Thunder Staff to Rank V.
Complete the Blacksmith Quest
Defeat 100 Carnivorous Plants
Defeat 300 Red Bees at daytime.
Defeat 100 Goblins
Defeat 30 Slimes
Defeat 100 Zombies
Survive for 2 minutes.
Survive for 5 minutes.
Survive for 12 minutes.
Survive for 15 minutes.
Defeat 300 Ghost Witches
Upgrade Fire Staff to Rank V.
Complete the Bloodmancer Quest
Defeat 30 Silver Werewolf
Win the Plaguelands Map in Corruption 9 with Vylat.
Win the Plaguelands Map in Corruption 9 with Rhys.
Win the Plaguelands Map in Corruption 9 with Allure.
Win the Plaguelands Map in Corruption 9 with Ninn.
Win the Plaguelands Map in Corruption 9 with Lance.
Win the Plaguelands Map in Corruption 9 with Veromus.
Win the Plaguelands Map in Corruption 9 with Lyah.
Win the Plaguelands Map in Corruption 9 with the Undine Familiar.
Win the Plaguelands Map in Corruption 9 with the Hoot Familiar.
Win the Plaguelands Map in Corruption 9 with the Salamander Familiar.
Win the Plaguelands Map in Corruption 9 with the Jinn Familiar.
Win a match without taking damage.
Collect 1000 blood gems.
Slain World Eater on Corruption 10 Leviathan's Lair.
Slain World Eater on Corruption 10 Plaguelands.
Beat Corruption 3 Without Take any Damage.
Defeat Vorax
Defeat Vorgron
In Endless Mode, make it until nightfall without taking damage
Beat the Scarlet Tower in Corruption 10
Collect 20 Re-roll dice in a single run
Collect 5 Equipment Banish in a single run
Beat Corruption 10 with the Knife of Darkness in your Arsenal
Buy something exclusive to Infinite Mode from the Seller
Win 5 matches using only magic weapons.
Defeat 1000 Pink Jellyfish in Leviathan's Lair