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
Disc puzzle completed
Stopped Peter and saved Emily!
Identified the mystery person
Emily is awaken!
All photos found
All evidence collected
The dragon defeated
Escaped the trap
Mystery of the painting solved
You got a revolver
Telescope puzzle completed
All special keys found
Got out of the dead end
Piano keys found
Courtyard reached
Record found
Mix puzzle completed
Coffin lid lifted
Books puzzle completed
Hex tile found
The fire is put out
Sliding puzzle completed
Pipes puzzle completed
Case a lion head
Animals puzzle completed
Got the Valve :)
Took the flashlight
Handkerchief evidence found
Gas up the car