Here is the full list of all 15 Zen Chess: Mate in Two achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Finish 150 Levels
Finish 140 Levels
Finish 130 Levels
Finish 120 Levels
Finish 110 Levels
Finish 100 Levels
Finish 90 Levels
Finish 70 Levels
Finish 80 Levels
Finish 60 Levels
Finish 50 Levels
Finish 40 Levels
Finish 30 Levels
Finish 20 Levels
Finish 10 Levels