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