Same thing for level 5-5, which is where you're fighting against oncoming waves of bungee zombies relying on nothing but Chompers, Pumpkins, Flower Pots, and Cherry Bombs. Crazy Dave sums it up at the start of the level.
Crazy Dave: You're gonna hate this level. It's one bungee zombie after another. I hate those bungee zombies. With a passion. And a vengeance. Here come those idiots now.