Here is the full list of all 42 Soul Survivors achievements.
Defeat the Ebon King
Defeat the Midnight Gatekeeper
Discover 15 Tomes of Knowledge
Defeat Bloodsap
Defeat Soulus
Use 3 Sacrifice Altars
Defeat Lady Nox
Kill 1,000 Skeletons
Survive 5 Curses
Defeat Velya
Collect Nibbler's Cheese in the Catacombs
Defeat Chancellor Autlaic
Collect 10,000 Souls
Burn 1,000 enemies with fire
Defeat Sporelord Rotwood
Defeat Warden Grainloch
Collect 500 Gold in a Single Run
Activate 3 Cursed Altars
Kill 5 Mimics
Kill 500 Zombies
Kill 1000 Flies
Defeat the Flesh Golem
Collect 1,000 Souls
Collect 100,000 Souls
Collect 1,000,000 Souls
Kill 50 Mimics
Max all Talents for the Bogatyr
Max all Talents for the Necromancer
Take No Damage for 5 Minutes
Take No Damage for 10 Minutes
Collect 100 Flesh Piles in a Single Run
Destroy an Entire Fly Swarm
Kill 1,000 Enemies with the Flail
Defeat Bilee
Max all Talents for the Ranger
Max all Talents for the Shadow Monk
Survive 10 Curses
Defeat Nibbler in Usvit Depths
Defeat the Ebon King without evading
Destroy 10 Gargoyle Statues in a single run
Max all talents for the Pyromancer
Max all talents for the Blood Maiden