Here is the full list of all 16 PowerWash Adventure achievements.
Complete the beginner level
Complete the News Car Level
The first completion of the haunted house level
Completion of Cleaning Any Graffiti Level
The first completion of Anubis
The first completion of the airplane level
The first completion of the UFO level"
Create and Save a Doodle Level for the First Time
The first completion of the piano
The first completion of the pool
The first completion of the truck
The first completion of the Robot
Completed a total of 10 normal levels
Accumulate 500 coins
Unlock the Intermediate Water Gun for the first time
Unlock and buy the first water gun accessory