Here is the full list of all 10 A Place, Forbidden achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Fail to find what you seek. [Acquire Ending 1]
You've found everything you need... [Acquire all Forbidden Knowledge]
Gain much more than you bargained for. [Acquire Ending 2]
Find a piece of that which will seal your fate. [Acquire your first piece of Forbidden Knowledge]
Begin your fruitless task. [Start cleaning up the Library]
Fine work, to be appreciated by no one. [Throw away all detritus]
The Librarian is displeased. [Act uncouthly with a printer]
You were meant to fail. [Attempt to open the door beyond your reach]
Quite the thespian, aren't you? [Read both play exerpts]
You broke down every barrier in your path. [Complete all primary puzzles]