G&G Mega Sunflower Exploit
There is a window on the right side of the tower that can be shot through and hit the sunflower whilst very far away. I'm guessing with how much work they put in to make it so you need to be inside that this is actually a pretty bad one. That level is hard enough as it is as a plant to defend let alone zombies that gather and shoot it from outside. It should have a self defense mechanism that if a whole clip is unloaded it return fire with a massive sunbeam. I Can't really think of any other exploits that are game breaking other than this one.
