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 In Sound Mind
Collect all pills in your building
Find all pills in the game
Collect all vinyl records
Finish Tape 5
Give Dave a high five while fighting for your mind
Finish Tape 4
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
Find all weapons in the game
Finish Tape 3
Collect all pills in the factory level
Trick The Bull into attacking an inkblot
Access top secret Mayer lab
Ride The Bull for 5 seconds
Acquire the Shotgun in your building
Finish Tape 2
Collect all pills in the lighthouse level
Damage The Shade using a weapon
Shoot down a Shade projectile
Shoot a crow
Acquire the Gas Mask in your building
Collect all pills in the supermarket level
Give a mannequin a face
Finish Tape 1
Hang up on your sneaky stalker
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