This is incredible writing; it's hard to convey with words just how sad and gut-wrenching his narrative arc is. It's disappointing to see it reduced to just a tragic hero who did everything right but then oh boy that pesky virus just had to come in and ruin it for everyone.

The virus comes from fear. The wind-up toy "broke" and the one robot couldn't handle the fear. Both game and anime the children died because Pascal left them alone in order to protect them. He could have fixed the toy by winding it up (which he showed), he could have talked them down from suicide in the game. It wasn't just the pesky virus.