Here is the full list of all 50 Foregone achievements.
Collect all Trophies
Max all possible nodes in Skill Mastery
Spare Project Zeus
Discover all secret locations
Discover all secret locations in a level
Acquire all Skill Upgrades
Hit 6 enemies with one Raze
Kill 10 enemies before Barrier's duration runs out
Damage 8 enemies with one Nova
Defeat an elite enemy inside Bastion
Max all possible nodes in the Skill Tree
Kill Project Zeus
Defeat Project Zeus
Acquire all collectibles
Acquire all Diary Pages
Defeat the revived Project Poseidon
Acquire all Military Reports
Equip a Mythic item in each active slot
Defeat the revived Project Demeter
Acquire all Lab Notes
Defeat the revived Project Hera
Acquire all Commander's Logs
Discover the Warden's plan
Complete a branch in the Skill Tree
Ascend to a secret location with Wall Climb
Acquire all Abilities
Defeat Project Poseidon
Learn the truth of the Arbiters
Acquire all Catalysts
Upgrade a Mythic item to Level 5
Acquire all Skills
Complete a branch in Skill Mastery
Defeat the King of Calagan
Acquire a Skill Upgrade
Damage 4 enemies with one Surge
Uncover a secret location with Ground Smash
Defeat Project Demeter
Kill 5 enemies with a single use of Overdrive
Defeat Tecton
Reminisce at the Courtyard
Defeat Project Hera
Allocate Essence into the Skill Tree
Upgrade an item
Destroy the Buzzbot
Speak to the Ferryman
Acquire a Catalyst
Discover a secret location
Heal with Restoration in mid-combat
Acquire a collectible
Complete the Prologue