Here is the full list of all 40 Dead achievements.
Complete DEAD with Boss Rush Mode and One Hit Mode enabled
Complete DEAD with Easy Mode, Boss Rush Mode and One Hit Mode enabled
Kill Dying Ember on Easy Mode
Kill Eight Bears in Easy Mode
Only use explosions when killing Dying Ember
Kill Eight Bears using only explosions
Kill The Silenced before killing Migraine
Summon the second ring
Complete DEAD in Easy Mode
Do not dodge when fighting Puppeteer
Never take damage when fighting Glass Master
Ring the bell
Never take damage from the clock
Kill Scourge without exploding
Never fire a bullet or explode when fighting Totem
Do not dodge when fighting Totem
Never dodge when fighting Glass Master
Kill Dying Ember
Kill Vesicle without leaving the bridge
Kill The Silenced within 60 seconds
Do not destroy any crystals
Kill Eight Bears
Never take damage when fighting Migraine
Never allow Smelter to get the sword
Kill Progenitor without moving
Kill Eremite first
Kill Scourge
Never dodge when fighting Furnace and Smelter
Kill The Silenced
Kill Progenitor without exploding
Kill Glass Master
Never allow Vesicle to heal
Kill Totem
Kill Puppeteer
Kill Migraine
Kill Furnace
Kill Eremite and Spectre
Kill Vescile
Kill Progenitor
Dead