Here is the full list of all 17 Ichi achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Get a score of 1000 points.
Get a score of 500 points.
Let 100 people play your level(s).
Create & Publish 10 levels.
Create & Publish 5 levels.
Complete 100 levels.
Complete 75 levels.
Let 10 people play your level(s).
Create & Publish 1 level.
Tap 1000 times.
Complete 50 levels.
Get a score of 100 points.
Complete 25 levels.
Tap 500 times.
Complete 10 levels.
Tap 100 times.
Complete 5 levels.