15 point!!!! mistake or joke

on chapter 135 when they are on mission to kill the dino
before there going gantz said that if they do not get 15 points or more
they will die
after the mission only kurono (if im not mistaken) got above 15 point
but the other got below 15 point
and nobody that been sending back to the room die
is it a joke from gantz or mistake

That sucked really bad if I was kurono too. Just after he got done saying he was just going to hide so he wouldn't die gantz is just like oh by the way i'll kill you if you don't get 15 points. owned