Here is the full list of all 50 Ori and the Blind Forest achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Complete the whole game without using an Ability Point
Finish the game in under 3 hours
Complete whole game without dying
Kill 500 enemies with Spirit Flame
Visit 100% of the map
Juggle a rock 5 times without it hitting the ground
Restore all Map Stones
Earn all skills in the Ability Tree
Earn all Combat Skills in the Ability Tree
Collect all Energy Cells
Find all secrets
Bash off enemies 10 times in a row without touching the ground
Save at every Spirit Portal
Collect all Health Cells
Kill 100 enemies with Charge Flame
Crush a Ram with a Stomper
Kill 5 enemies with Charge Jump
Find the lost corridor in the Misty Woods
Double Jump 5 times consecutively without touching the ground
Complete the game
A beloved bond
Fan the flames
Kill 50 enemies with Stomp
Enter Mt. Horu
Collect 200 Energy Shards
Earn all Efficiency Skills in the Ability Tree
Create 50 Soul Links
Kill 25 enemies using Bash to reflect projectiles
Climb to the top of Nibel
Find 50% of all secrets
Have a close encounter
Restore the winds of Nibel
Earn all Utility Skills in the Ability Tree
Clear the haze from the Misty Woods
Trick 5 enemies into killing another enemy
Restore 50% of all Map Stones
Escape a dangerous situation
Cleanse the Ginso Tree's Heart
Enter the Ginso Tree
Kill 3 enemies without touching the ground
Make an unexpected friend
Cause an enemy to destroy itself
Discover the character in the shadows
Break open 5 shortcuts using the Charge Flame
Kill 4 enemies simultaneously using Charge Flame.
Meet the Ancient Being
Restore your first Map Stone
Find your first secret
Use your first ability point
Complete the Prologue