Here is the full list of all 14 The Last Tinker: City of Colors achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Give your eyes a hard time.
Collect every Floaty Brush in the game.
Buy every combat move in the Dojo.
Colorize all the Purple paintings in Purple's dream world.
Shoot the moon at Blue Harbor.
Punch a very special crate.
Find the hermit living in the turtle cave.
Send one of the Greens flying in the Market District.
Conduct the orchestra without making a mistake.
Defeat the Final Boss.
Solve the crime at Blue Creek.
Defeat the Boss at Blue Harbor.
Reach the highest point of the Great Windmill.
Reach the Tower Gallery.