It is difficult. It is obtuse. And it requires you to actively lose in order to win. But that is the point of an "Extra Life"—you only get it after you've already used up the one you were given.
: Key actions include visiting her computer (turn off WiFi first) and keeping her secrets, particularly regarding her MP3 player. goodbye eternity walkthrough aka extra life
Here’s the exact sequence to trigger the secret ending known as (sometimes called the "Goodbye, Eternity" true ending). It is difficult