Here is the full list of all 18 Picross Touch achievements. It takes around 30-35 hours to unlock all of the achievements on Windows.
Completed the tutorial.
All original 5x5 levels complete.
All original 10x10 levels complete.
All original 15x15 levels complete.
All original levels complete.
Submitted a 5x5 puzzle to the workshop.
Submitted a 10x10 puzzle to the workshop.
Submitted a 15x15 puzzle to the workshop.
Submitted a 20x20 puzzle to the workshop.
Completed a total of 10 puzzles.
Completed a total of 25 puzzles.
Completed a total of 50 puzzles.
Completed a total of 100 puzzles.
Completed a total of 200 puzzles.
Completed a total of 500 puzzles.
Completed a total of 750 puzzles.
Completed a total of 1000 puzzles.
Completed a total of 2000 puzzles.