Here is the full list of all 35 HENTAI PUZZLE achievements.
Skip the story dialogues 20 times
Clicked the next puzzle button in the first stage
Complete the first puzzle
Click the hint button 30 times
Click *yourself* back to the menu
Skip the Introduction story
Turn off the In-Game Music
Complete the second puzzle
Complete the second second puzzle
Complete the cow puzzle
Pressed against the glass
Slowly pressed against the glass
Get over here
Hands On
What a mouthful
Sticky Eggplant
Couchtime
Sushi???
Complete the game
Skip the story dialogs 200 times
Start a new game with progress of a least 5 completed puzzles
Complete 5 Puzzles
Complete a puzzle without using the hint button
You noticed you have a small dick to play with
Click a tiny dick 5 times
Click a tiny dick 10 times
Click a tiny dick 20 times
Click a tiny dick 50 times
Click a tiny dick 100 times
Click a tiny dick 200 times
Click a tiny dick 500 times
Click a tiny dick 1000 times
Click a tiny dick 5000 times
Click a tiny dick 9001 times
Click a tiny dick 10000 times