Here is the full list of all 30 Hope Lake achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Get into boarding school
Pipes puzzle completed
Disc puzzle completed
Case a lion head
Took the flashlight
Animals puzzle completed
Got the Valve :)
Handkerchief evidence found
Gas up the car
Coffin lid lifted
Record found
All special keys found
You got a revolver
Mystery of the painting solved
Escaped the trap
All evidence collected
Identified the mystery person
All photos found
Courtyard reached
Mix puzzle completed
Got out of the dead end
Emily is awaken!
The dragon defeated
Stopped Peter and saved Emily!
Telescope puzzle completed
Books puzzle completed
Sliding puzzle completed
Hex tile found
Piano keys found
The fire is put out