Here is the full list of all 43 Chronos: Before the Ashes achievements.
Defeat the Krell Guardian
Defeat the Pan Guardian
Defeat the Labyrinth Guardian
Defeat the Dreamer
Defeat the Stone Golem
Defeat the Red Widow
Travel to Ward 16 by Way of the Mirror
Craft a Krell Mace
Meet the Krell Blacksmith
Acquire the Krell Hammer
Acquire the Labyrinth Scythe
Acquire the Pan Spear
Acquire the Krell Shield
Acquire the Pan Shield
Acquire the Krell Hidden Weapon
Upgrade Any Weapon
Upgrade Any Weapon to Level +5
Meet the Pan Flautist
Acquire the Fire Stone
Acquire the Lightning Stone
Acquire the Sun Stone
Acquire the Shadow Stone
Solve the Flautist Riddles
Unlock Your First Trait
Put 30 Attribute Points into Strength
Put 30 Attribute Points into Agility
Put 30 Attribute Points into Arcane
Put 30 Attribute Points into Vitality
Complete the Game at age 21 or younger
Read 5 Books or Scrolls
Read 10 Books or Scrolls
Exchange your Starting Weapon with a Krell Version
Acquire a Dragon Heart
Create a Rare Dragon Shard
Open a Dragon Inscribed Box
Return a Keepsake to the Krell King
Complete the Game on HEROIC
Complete the Game on any Difficulty
Complete the Game on ADVENTURE
Unlock Everything
Upgrade Any Weapon to Level 9
Complete the Game in NG+ Mode