Here is the full list of all 17 Midnight Dash achievements.
You used dash for the first time!
You found Tea Shop's secret house!
You unlocked a new ability Dash!
Secret way to skip some parts of the level!
Magical secret gem that follows you? I wonder what it does?
You found what the secret gem does!
You found a secret shop that doesn't sell anything...
You defeated Perrigwyn!
yeah.. you found my testing room..
You defeated Dilki!
You managed some how to escape from Dunrey.. wow... that was scary!
Complete Nightmare bonus level!
Defeat Grimm in Nightmare bonus level!
Hey cratz you defeated God..?
I see you talked to Cass.. i wonder who Dean is?
Complete Perrigwyn's bonus level..?
You have friends?