Here is the full list of all 12 Hentai Casual Swap achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Thanks for playing Hentai Casual Swap!
Visit the gallery for the first time.
Use the help button for the first time.
Unlock Level 2.
Unlock Level 3.
Unlock Level 4.
Unlock Level 5.
Unlock Level 6.
Unlock Level 7.
Unlock Level 8.
Unlock Level 9.
Unlock Level 10.