Please refer to Carrigon's walkthrough if you are stuck on the game:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1654410629
The purpose of this guide is to just specify when achievements unlock as they aren't covered in the guide above.

Come to me all bears - Collect all bears
• room 3 - hanging in the top-right corner, requires knife to cut down
  room 4 - in the shadows in the top-right corner
  room 7 - in the dark in the lower-right corner, slide it aside before picking it up
  room 8 - in the dark on the right side
  secret room - in the dark in the lower-right
  room 11 - behind the slidable chest in the centre of the room
  room 15 - on a shelf in the dark on the right side
  room 16 - in the dark on the right side

112 - Call the police
• room 1 - call 112 as game instructs you.

Spider - I'm not afraid!
• room 2 - find it in the dark on right edge of screen. also appears in other rooms.

Shoe - Find a robert shoe
• room 3 - pick up the shoe near evidence marker 4.

Hacker - Break the password on any computer
• room 3 - unlock the computer. computers are also in other rooms.

Birthday candle - Light a candle
• room 4 - light the candle under the operating table.

Clown - First contact
• room 5 - lower right corner, view with light source.

Chuck - Meet a Chuck
• room 5 - solve the room as per normal by sliding a picture to find a key. use the key to unlock a chest to begin a chase sequence with chuck.

Robert & Patrick secret - Find a secret...
• secret room - open the secret door in room 9.

The great escape - Finish the game
• room 19 - escape the coffin (must save either patrick or sara or both).