Here is the full list of all 23 The Innsmouth Case achievements.
Spent a night with Dahlia
Became friends with Jonah
Used dirty methods to avoid payment
Overpowered the gawper
Found a couple of weird City Hall records
Played a creepy Arcade Game
Discovered fragments from Innsmouth’s history
Didn’t touch the cube in the lighthouse
Wendy found a safe place
Slept with Priscilla
Slept with a fish creature
Snooped through an abandoned hotel room
Wrongdoings have consequences
Survived a night in the Gilman Hotel
Dahlia spared your life
Snooped through the Marsh Family records
Seduced Ethel
Pissed Dahlia off to death
Saved from the stake
Traumatized Evelyn
Played through all endings
Discovered all of Innsmouth
Mentioned your vegan lifestyle 3 times