I'd definitely love an alternate ending scenario. Maybe waiting long enough makes Annihalator chan process things in the long silence. Or going for self first. Perhaps self first causes a stubborn AC to stop you.
Well as I mentioned, I think the idea of more interactions with Annihilator chan could be cute. Including the despair of long silence with no one left. There is also her stopping you from going first possibly causing a reconsidering. Consider it a "gameover" for failing to complete the annihilation due to both your minds changing.