The reason I think that is because, from my perspective, it gets a bit too annoying in difficulty. Basic & Conehead Zombies are fine enough to deal with. Bucketheads are a force, but they're aigh'... Newspaper & Pole Vaulter Zombies, however, is where it all goes downhill for me. The former is as tough as a Conehead in this minigame, but the moment it decides to speed-up after losing its newspaper can prove to be a real pain the ass when I decided to leave this Zombies off for a pinch later (& I do mean a pinch - with the clusterfuck of Zombies coming my way, there's no time for rest). Pole Vaulters are a completely different & way worse can of worms - most of the time, these bastards jump over Wall-Nuts rolling their way & only then do they become vulnerable. Before that, however, they're still a burden: the way they run rather quickly is concerning. Fortunately, their jumping can be negated if I let them cross the red line & then plant a Wall-Nut right at their face; instantly knocks them out cold. It's easy precision, but with fuckers like Pole Vaulters, it's basically mandatory.