Ground Control to Psychoelectric Angel is the ending you receive for getting the Affection meter to 100%. This is not a necessarily difficult task, and can be done quickly by spending time with Ame through tasks that increase the affection meter. One problem I faced that is easy to bump into is accidentally getting the Normie Life ending to getting Mental Darkness to 0, as having *** drops the Mental Darkness meter, but is a very quick Affection booster. Using the Spend Time Together option doesn't boost Affection as fast, but keeps Mental Darkness at bay. Use them both if you need to. Good luck.