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.
Collect all pills in your building
Find all pills in the game
Collect all vinyl records
Collect all pills in the forest level
Find Rosemary's secret song
Find and listen to all of Lucas' session fragments
Stun The Flash using your Radio Device
Collect all pills in the factory level
Ride The Bull for 5 seconds
Finish In Sound Mind
Collect all pills in the lighthouse level
Shoot down a Shade projectile
Shoot a crow
Give a mannequin a face
Collect all pills in the supermarket level
Finish Tape 5
Give Dave a high five while fighting for your mind
Finish Tape 4
Find all weapons in the game
Pet Tonia
Finish Tape 3
Trick The Bull into attacking an inkblot
Access top secret Mayer lab
Acquire the Shotgun in your building
Finish Tape 2
Damage The Shade using a weapon
Acquire the Gas Mask in your building
Finish Tape 1
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
Hang up on your sneaky stalker