Most likely this will be the only end game achievement most people get.
This is for completing the game without finding all 5 Moura Tears. You can find any other secrets, but must NOT collect all 5.
Once you get to Moura you will fight her like normal, but the gate will fail to open and take you to Level 8, which will then give you the "bad" ending.
You can die and use as many continues as you like.