You know, you must have spent lot of time selecting the BGs, choosing which is better until we reach the best from min upgrade to max, altough most of the players just save up the money and skip through the whole thing to the max.
Ok the Zombie guy is pretty easy. Here's what you need to do: Get the poison sword on the stages before and keep it. But it is not necessary. Shoot rocks at him, then keep jumping up to his face and hitting him. When you're cornered, let him hit you once. Rage, hit him, while his charging eat fruits, then hit him again, and at the second charge jump over him with Sprint+jump. If you throw food at him, he'll charge. If you sprint attack him he will charge. Just jump over his charges, and keep hitting his face.