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