Found a cheese with zombie control, the game becomes broken because to many zombies being controlled at once. Simply focus on control upgrades and relax as watching the fps drop.
Thanks for playing! And sorry about the zombies, I couldn't think of a good fix besides nerfing control spread into the ground so it does get a bit unbalanced xD
EDIT: Might convert the zombies controlled button into a limit for controlled zombies, but that's for after the jam :)