Here is the full list of all 32 In Sound Mind achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Finish Tape 2
Finish Tape 3
Finish Tape 4
Finish Tape 5
Finish In Sound Mind
Collect all pills in the lighthouse level
Collect all pills in the factory level
Collect all pills in the forest level
Collect all pills in your building
Collect all vinyl records
Acquire the Shotgun in your building
Shoot a crow
Damage The Shade using a weapon
Shoot down a Shade projectile
Ride The Bull for 5 seconds
Access top secret Mayer lab
Trick The Bull into attacking an inkblot
Find and listen to all of Lucas' session fragments
Find Rosemary's secret song
Stun The Flash using your Radio Device
Give Dave a high five while fighting for your mind
Find all weapons in the game
Find all pills in the game
Acquire the Gas Mask in your building
Finish Tape 1
Collect all pills in the supermarket level
Give a mannequin a face
Scare The Watcher away using the Mirror Shard
Push a cart into the water on the way to Homa Mart
Acquire the Pistol in your building
Pet Tonia
Hang up on your sneaky stalker