Here is the full list of all 23 Sexual Void achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Unlock all the full bodies
Unlock all the shirts
Unlock all the stockings
Unlock all the skirts
Complete the 20 minutes JOI
Unlock all the panties
Unlock all the bras
Complete the 10 minutes JOI
Unlock all the hairstyles
Complete the 5 minutes JOI
No orgasm today, retry tomorrow
Ruin your orgasm and eat it
Eat your orgasm
Unlock all the skins
Ruin your orgasm
Complete the 1 minute JOI
Complete your first orgasm in the Void
Unlock the 80's Void
We like to call him Rodolfo
Unlock all the accessories
Unlock all the eyes
Use the panic button
Enter for the first time in the Sexual Void