Here is the full list of all 50 Ori and the Blind Forest achievements worth 1,000 gamerscore.
Completed whole game without dying
Completed the whole game without using an Ability Point
Finished the game in under 3 hours
Completed the game
Reunited with Naru
Restored the Element of Warmth
Visited 100% of the map
Restored all Map Stones
Found all secrets
Collected all Energy Cells
Entered Mt. Horu
Earned all Utility Skills in the Ability Tree
Earned all Skills in the Ability Tree
Saved at every Spirit Portal
Earned all Efficiency Skills in the Ability Tree
Earned all Combat Skills in the Ability Tree
Killed 5 enemies with Charge Jump
Collected all Health Cells
Obtained the Sunstone
Juggled a rock 5 times without it hitting the ground
Found the lost corridor in the Misty Woods
Escaped Kuro
Restored the winds of Nibel
Cleared the Misty Woods
Found 50% of all secrets
Restored 50% of all Map Stones
Killed 50 enemies with Stomp
Killed 500 enemies with Spirit Flame
Killed 25 enemies using Bash to reflect projectiles
Collected 200 Energy Shards
Bashed off enemies 10 times in a row without touching the ground
Escaped the rising waters of the Ginso Tree
Restored the heart of the Ginso Tree
Double Jumped 5 times consecutively without touching the ground
Entered the Ginso Tree
Killed 100 enemies with Charge Flame
Opened 5 shortcuts using the Charge Flame
Created 50 Soul Links
Rescued Gumo
Caused an enemy to destroy itself
Crushed a Ram with a Stomper
Tricked 5 enemies into killing another enemy
Discovered Gumo
Killed 4 enemies simultaneously using Charge Flame.
Killed 3 enemies without touching the ground
Restored your first Map Stone
Met the Spirit Tree
Used your first ability point
Found your first secret
Completed the Prologue