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