Here is the full list of all 14 The Magic Circle achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Old Pro had to do it for you
Pushed the button because you got bored
From this point on, you will have to exhaust your own content.
Hell hath no fury like a tester scorned.
The boundaries of this simulation have no hold on you.
This can only be...
There is no keypad here, but you did it anyway
Your Words Go Here
You will be known as the person who made that thing.
Remembered your first when it mattered
Got enough of Starfather's speech to make a proper mixtape
What kind of boss fight was that?
Embrace the null state
More like... Finished the "game".