1. Buy full version. You could do this with a bit eventing. I can make a random weapons box using variable/conditional events. To direct them to the windows, you could make them step over a brick and that will set zombie target to that spot. Turn the brick damage off and make the windows: onBotTouch>Self>FakeKillBrick> -1 so it vanished completely and another brick appears on the floor that you have to click to repair it. To make the zombies get stronger, set boxes that open after all of the zombies before it are killed. Then onZombieDeath>Clientr>AddVariable. That can be used for the score.
So you don't need anymore new things when you can do it like that...