Here is the full list of all 39 Opus Castle achievements.
Get run over
Take a look around on the town
Play with the goat
Find the base key
Collect the cassette player
Use your cell phone flashlight
Access the company's app
Change the cell phone's wallpaper
Try to run
Interact with the mirror
Check up the stairs
Enter the suite
Enter Alvaro's bedroom
Enter the dinner room
Go to the entrance
Find pin 1 of the key
Find pin 2 of the key
Find pin 3 of the key
Steal the jewels
Collect the pot of mugwort
Take a deep breath with the cigarette
Get a drink
Drink until fall
Collect the invocation tape
Collect the Gun
Eat a little
See the photo of the hall
See the photo of the suit
See the photo of Alvaro's bedroom
See the pictures of the office
Open the drawers
Collect 3 items
Interact with 3 verifiable items
Interact with 7 verifiable items
Final Suit
Ending Room of Álvaro
Ending Dinner room
Final Office Room
Achieve all achievements