Alright, let me float my idea for what would have been the greatest ending to this movie of all time, and lets discuss.
It was clear to me from the moment I knew this movie was on a different planet, all the humans had to die. There is not a way to let anyone survive without being super cheesy. Even if they did then what? So kill them all off first, hard fought battles and the like of course. Then the final battle should have been OP VS BSP ending with OP taking BSP skullnspine as a trophy. He raises his trophy and lets out that classic predator scream, cut to credits.