Blood Easter Egg - "E1m6 Super Secret"

1. In the room where you acquire the moon key jump down into the clouds (when you land you should be against the wall).

2.Walk along the invisible ledge until you enter a room.

3. You will be told that they can't believe you found it, and they give you a lot of stuff including invulnerability.

4. Grab the invulnerability and jump off.

5. Look for the message.