Playdead's Inside Hack -

: You must backtrack to a hidden bunker under the cornfield (near the location of the second orb). A previously locked door there now responds to a musical code: Up, Up, Right, Left, Right, Right, Right, Up, Up, Up, Right, Left, Left, Left . The "Hack": What the Ending Means

To unlock this hidden conclusion, you cannot simply reach the end of the narrative. You must meticulously dismantle the game's infrastructure by finding and destroying scattered throughout the world. Playdead's INSIDE Hack

: Some theorists believe this is the only "good" ending. It allows the boy to escape the cycle of experiments and the "Huddle" (the mass of flesh found in the standard ending) by choosing a definitive end rather than becoming part of a hive mind. : You must backtrack to a hidden bunker