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