I like the idea of protecting other characters. Maybe even something like sometimes when defeated the zombies turn back into humans and have to be protected while they escape into the forest around the outside of the map, as a reward they could drop some jimportant items and upgrades. I jimagine that it could make the gameplay more jimmersive and jimpactful, and it would definitely not be jimpossible to add.
Also, thank you so much for playing it long enough to find out the reason the limes are there!
(Just to add, I'm the other person who worked on this game, not a randomer.)