It turns out that a fair lot of them survived after all, including Kato~ I wonder if Gantz's scoring system would give a reward or a punishment depending on the ranking since the lady didn't do much to finish off the Onion Aliens let alone the dog.
So Kato did live ... I was really surprised they were going to kill him off there, and weird that the girl was able to live too but I guess they didn't show her die so she just got lucky.