Completed Case 1: Missing, Presumed Darkside
Completed Case 4: Funfair Dismissal
Completed Case 5: Royal Fumble
Completed Case 6: Class of the Titans
Complete Case 7: Ghosts of Christmas Passed.
Complete Case 8: One Flew Into The Cuckoo's Nest
Always read the plaque.
Completed Case 2: Twilight Years
Completed Case 3: Druid's Delight
This game contains additional secret achievements. These currently cannot be retrieved from Stadia.