Here is the full list of all 11 SEXTS achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Complete 10 words!
Complete 25 words!
100 letters written!
500 letters written!
Collect 10 witches!
Collect 10 animal girls!
Collect 10 maids!
Start your first game!
You missed 5 times!
Save a picture in the gallery
Finish a level in Very Hard!