For me, what seperates Shaun from other parodies is it basically takes the idea of shambling zombies, inserts a bunch of hilarious characters and then examines it. That's it's thesis. What would ACTUALLY happen if slow zombies attacked, what would actually be the threat level. they come up with this, yes, it's stupid to think one zombie, if you know what they are, is dangerous. Because they are incredibly easy to kill, and they mine that so well in the first half. But then they realise, when zombies come in packs, in large mobs, they are terrifying and horrific. And then you are in incredible danger. At that is the final act.