I find it funny that the human in the first level expected the tent to protect her from animals similar to how a child expects a blanket to protect them from monsters.
Kelly's apparently an idiot. About 20 zombies dropped from the roof and she just stood there with her shotgun when I could have kept them off of her with my heavy nail board.
Final Strategy: 2 entropy aliens, 1 scarface, 1 shadowkiller. The scarface will get in the way of ranged knockback attacks (ie: soul seeker) while still acting as a lesser entropy alien.
A quick revision to the strategy I posted a bit ago, the only thing missing was upgrades to the entropy aliens.
It hasn't lost yet since I upgraded them a few times.