Here is the full list of all 19 Wandering Skies achievements.
Use the rollback for the first time
Finish a level with all collectibles
Finish the first 3 levels
Finish the first 6 levels
Finish the game
Finish a level without dying
Finish the game without dying
Fall 10 times in the hub
Be killed by every mean possible
Pick up all possible types of gun
Finish 3 levels with all collectibles
Finish the game with all collectibles
Charge a shot during 60 seconds
Finish the game without any collectibles
Break 50 pots
Destroy a projectile with another
Finish a level without taking any checkpoint
Finish the game without dying, with all collectible and without taking any checkpoint